scons: don't die on warnings in swig-generated code

There's not much to do about it other than disable the offending
warning anyway, so it's not worth terminating the build over.

Also suppress uninitialized variable warnings on gcc (happens
at least with gcc 4.4 and swig 1.3.40).

src/SConscript

@@ -892,7 +892,6 @@ def makeEnv(label, objsfx, strip = False, **kwargs):
     new_env.Append(**kwargs)
 
     swig_env = new_env.Clone()
-    swig_env.Append(CCFLAGS='-Werror')
 
     # Both gcc and clang have issues with unused labels and values in
     # the SWIG generated code
@@ -904,8 +903,10 @@ def makeEnv(label, objsfx, strip = False, **kwargs):
 
     if env['GCC']:
         # Depending on the SWIG version, we also need to supress
-        # warnings about missing field initializers.
-        swig_env.Append(CCFLAGS='-Wno-missing-field-initializers')
+        # warnings about uninitialized variables and missing field
+        # initializers.
+        swig_env.Append(CCFLAGS=['-Wno-uninitialized',
+                                 '-Wno-missing-field-initializers'])
 
         if compareVersions(env['GCC_VERSION'], '4.6') >= 0:
             swig_env.Append(CCFLAGS='-Wno-unused-but-set-variable')