osx: Don't warn about unkown warning option

zcbenz · zcbenz · commit 70af2e0bee5c · 2015-09-10T11:15:35.000+08:00
We can not make every compiler happy.
diff --git a/common.gypi b/common.gypi
@@ -75,6 +75,7 @@
         'xcode_settings': {
           'GCC_TREAT_WARNINGS_AS_ERRORS': 'NO',
           'WARNING_CFLAGS': [
+            '-Wno-unknown-warning-option',
             '-Wno-parentheses-equality',
             '-Wno-unused-function',
             '-Wno-sometimes-uninitialized',
