Revert of [build] Switch off warning on gcc bots.

gypfiles/standalone.gypi

Index: gypfiles/standalone.gypi
diff --git a/gypfiles/standalone.gypi b/gypfiles/standalone.gypi
index 4c026c1a7bd9a910a7ca503a9bf524855f7ce873..7e41ce84aef96d1b2d5f0c8ca23c10a12334893f 100644
--- a/gypfiles/standalone.gypi
+++ b/gypfiles/standalone.gypi
@@ -503,10 +503,7 @@
     },
     'conditions':[
       ['clang==0', {
-        'cflags+': [
-          '-Wno-sign-compare',
-          '-Wno-maybe-uninitialized',
-        ],
+        'cflags+': ['-Wno-sign-compare',],
       }],
       ['clang==1 or host_clang==1', {
         # This is here so that all files get recompiled after a clang roll and