Bug 1338876 - Read ww-auth properly. r=mcmanus

--HG--
extra : rebase_source : 61d54449f04d82ff58358315917558f276bba326

netwerk/protocol/http/nsHttpDigestAuth.cpp

@@ -566,8 +566,8 @@ nsHttpDigestAuth::ParseChallenge(const char * challenge,
   if (strlen(challenge) > 16000000) {
     return NS_ERROR_INVALID_ARG;
   }
-  
-  const char *p = challenge + 7; // first 7 characters are "Digest "
+
+  const char *p = challenge + 6; // first 6 characters are "Digest"
 
   *stale = false;
   *algorithm = ALGO_MD5; // default is MD5