Include config.h in src/config.cafile.c

See <https://github.com/profanity-im/profanity/issues/1512>

src/config/cafile.c

@@ -33,6 +33,8 @@
  *
  */
 
+#include "config.h"
+
 #include <fcntl.h>
 #include <glib.h>
 #include <errno.h>