clientloader: don't fallback to Jagex hostnames when using fallback config

runelite-client/src/main/java/net/runelite/client/rs/ClientLoader.java

@@ -390,7 +390,8 @@ public class ClientLoader implements Supplier<Applet>
 				{
 					log.warn("Failed to download gamepack from \"{}\"", url, e);
 
-					if (attempt >= NUM_ATTEMPTS)
+					// With fallback config do 1 attempt (there are no additional urls to try)
+					if (config.isFallback() || attempt >= NUM_ATTEMPTS)
 					{
 						throw e;
 					}