Drop -Werror

Index: configure
--- configure.orig
+++ configure
@@ -14091,7 +14091,7 @@ $as_echo "#define AC_APPLE_UNIVERSAL_BUILD 1" >>confde
 
 # These options are GNU compiler specific.
 if test "x$GCC" = "xyes"; then
-    CPPFLAGS="-pedantic -Werror -Wall -Wc++-compat ${CPPFLAGS}"
+    CPPFLAGS="-pedantic -Wall -Wc++-compat ${CPPFLAGS}"
 fi
 
  if test "x$enable_shared" = "xyes"; then