Unit test: Disable unknown pragma warning for unit tests

test/civetweb_check.h

@@ -28,6 +28,7 @@
 #endif
 #if defined(__MINGW__) || defined(__GNUC__)
 #pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wunknown-pragmas"
 #pragma GCC diagnostic ignored "-Wno-variadic-macros"
 /* Disable warnings for defining _CRT_SECURE_NO_* (here) and
  * _CHECK_CHECK_STDINT_H (in check.h)