MDEV-10788 Not able to compile source with -DBUILD_CONFIG=mysql_release -DCMAKE_BUILD_TYPE=Debug

fix incorrect merge, 831b5318 was not fully merged into 10.0

config.h.cmake

@@ -663,21 +663,4 @@
 #define __STDC_FORMAT_MACROS
 #endif
 
-/*
-  stat structure (from <sys/stat.h>) is conditionally defined
-  to have different layout and size depending on the defined macros.
-  The correct macro is defined in my_config.h, which means it MUST be
-  included first (or at least before <features.h> - so, practically,
-  before including any system headers).
-
-  Check the include order by looking at __GLIBC__ (defined in <features.h>)
-
-  But we cannot force all third-party clients/connectors to include
-  my_config.h first. So, their crashes are their responsibility,
-  we enable this check only for MariaDB sources (SAFE_MUTEX check).
-*/
-#if defined(__GLIBC__) && defined(SAFE_MUTEX)
-#error <my_config.h> MUST be included first!
-#endif
-
 #endif