Cleaner code using nil messaging

src/objective-c/GRPCClient/private/GRPCHost.m

@@ -143,10 +143,8 @@ static NSMutableDictionary *gHostCache;
 
   GRPCCallOptions *callOptions = nil;
   @synchronized(gHostCache) {
-    if ([gHostCache objectForKey:host]) {
     callOptions = [gHostCache[host] callOptions];
   }
-  }
   if (callOptions == nil) {
     callOptions = [[GRPCCallOptions alloc] init];
   }