Relax (i.e. remove all checks) on the hostname.

While validating this is a good idea, it causes too many issues in
practice. We will still clean the server address but no validation is
performed on the address.

proxy/src/main/java/com/velocitypowered/proxy/connection/ConnectionType.java

@@ -42,6 +42,6 @@ public interface ConnectionType {
    * @return true if valid.
    */
   default boolean checkServerAddressIsValid(String address) {
-    return !address.contains("\0");
+    return true;
   }
 }

proxy/src/main/java/com/velocitypowered/proxy/connection/forge/legacy/LegacyForgeConnectionType.java

@@ -31,10 +31,4 @@ public class LegacyForgeConnectionType extends ConnectionTypeImpl {
 
     return original;
   }
-
-  @Override
-  public boolean checkServerAddressIsValid(String address) {
-    return super.checkServerAddressIsValid(
-        address.replaceAll(LegacyForgeConstants.HANDSHAKE_HOSTNAME_TOKEN, ""));
-  }
 }