Bug 1140656 - Disable test_socks.js on mac debug for frequent failures. r=jmaher

Differential Revision: https://phabricator.services.mozilla.com/D29967

--HG--
extra : moz-landing-system : lando

netwerk/test/unit/xpcshell.ini

@@ -318,7 +318,7 @@ fail-if = os == "android"
 [test_simple.js]
 [test_sockettransportsvc_available.js]
 [test_socks.js]
-skip-if = (verify && (os == 'mac'))
+skip-if = (verify && (os == 'mac')) || (debug && (os == 'mac')) #Bug 1140656
 # Bug 675039: test fails consistently on Android
 fail-if = os == "android"
 # http2 unit tests require us to have node available to run the spdy and http2 server