tests/server: fix initialization on Windows Vista+

Make sure to call `curlx_now_init()` before the first call to
`curlx_now()`.

Before this patch the first `curlx_now()` used the non-Vista code path
calling `GetTickCount()` on Vista+. This is harmless, but the upcoming
PR #18009 is going to drop the non-Vista code path, causing a division
by zero at startup in test servers, without this fix.

Bug: https://github.com/curl/curl/pull/18009#issuecomment-3652154307

Closes #19973

tests/server/dnsd.c

@@ -474,11 +474,6 @@ static int test_dnsd(int argc, char **argv)
   snprintf(loglockfile, sizeof(loglockfile), "%s/%s/dnsd-%s.lock",
            logdir, SERVERLOGS_LOCKDIR, ipv_inuse);
 
-#ifdef _WIN32
-  if(win32_init())
-    return 2;
-#endif
-
 #ifdef USE_IPV6
   if(!use_ipv6)
 #endif

tests/server/first.c

@@ -51,5 +51,10 @@ int main(int argc, char **argv)
     return 99;
   }
 
+#ifdef _WIN32
+  if(win32_init())
+    return 2;
+#endif
+
   return entry_func(argc - 1, argv + 1);
 }

tests/server/mqttd.c

@@ -822,11 +822,6 @@ static int test_mqttd(int argc, char *argv[])
   snprintf(loglockfile, sizeof(loglockfile), "%s/%s/mqtt-%s.lock",
            logdir, SERVERLOGS_LOCKDIR, ipv_inuse);
 
-#ifdef _WIN32
-  if(win32_init())
-    return 2;
-#endif
-
   CURLX_SET_BINMODE(stdin);
   CURLX_SET_BINMODE(stdout);
   CURLX_SET_BINMODE(stderr);

tests/server/resolve.c

@@ -83,11 +83,6 @@ static int test_resolve(int argc, char *argv[])
     return 1;
   }
 
-#ifdef _WIN32
-  if(win32_init())
-    return 2;
-#endif
-
 #ifdef CURLRES_IPV6
   if(use_ipv6) {
     /* Check that the system has IPv6 enabled before checking the resolver */

tests/server/rtspd.c

@@ -1100,11 +1100,6 @@ static int test_rtspd(int argc, char *argv[])
   snprintf(loglockfile, sizeof(loglockfile), "%s/%s/rtsp-%s.lock",
            logdir, SERVERLOGS_LOCKDIR, ipv_inuse);
 
-#ifdef _WIN32
-  if(win32_init())
-    return 2;
-#endif
-
   install_signal_handlers(false);
 
 #ifdef USE_IPV6

tests/server/sockfilt.c

@@ -1313,11 +1313,6 @@ static int test_sockfilt(int argc, char *argv[])
     }
   }
 
-#ifdef _WIN32
-  if(win32_init())
-    return 2;
-#endif
-
   CURLX_SET_BINMODE(stdin);
   CURLX_SET_BINMODE(stdout);
   CURLX_SET_BINMODE(stderr);

tests/server/socksd.c

@@ -875,11 +875,6 @@ static int test_socksd(int argc, char *argv[])
     }
   }
 
-#ifdef _WIN32
-  if(win32_init())
-    return 2;
-#endif
-
   CURLX_SET_BINMODE(stdin);
   CURLX_SET_BINMODE(stdout);
   CURLX_SET_BINMODE(stderr);

tests/server/sws.c

@@ -2159,11 +2159,6 @@ static int test_sws(int argc, char *argv[])
            logdir, SERVERLOGS_LOCKDIR, protocol_type,
            is_proxy ? "-proxy" : "", socket_type);
 
-#ifdef _WIN32
-  if(win32_init())
-    return 2;
-#endif
-
   install_signal_handlers(false);
 
   req = calloc(1, sizeof(*req));

tests/server/tftpd.c

@@ -647,11 +647,6 @@ static int test_tftpd(int argc, char **argv)
   snprintf(loglockfile, sizeof(loglockfile), "%s/%s/tftp-%s.lock",
            logdir, SERVERLOGS_LOCKDIR, ipv_inuse);
 
-#ifdef _WIN32
-  if(win32_init())
-    return 2;
-#endif
-
   install_signal_handlers(true);
 
 #ifdef USE_IPV6