cmake: don't error on apple when using deprecated declarations

configure

@@ -23001,8 +23001,8 @@ printf "%s\n" "$have_gcc_werror" >&6; }
 
 CheckNoErrorDeprecatedDeclarationsWerror()
 {
-    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for GCC -Werror option" >&5
-printf %s "checking for GCC -Werror option... " >&6; }
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for GCC -Wno-error=deprecated-declarations option" >&5
+printf %s "checking for GCC -Wno-error=deprecated-declarations option... " >&6; }
     have_gcc_no_werror_deprecated_declarations=no
 
     save_CFLAGS="$CFLAGS"