Fix inefficient loop in QueryStringDecoder.decodeComponent()

- Fixes #2228
- There's no point of looping until the end of the component if at least one '%' or '+' is found.

codec-http/src/main/java/io/netty/handler/codec/http/QueryStringDecoder.java

@@ -311,13 +311,9 @@ public class QueryStringDecoder {
         boolean modified = false;
         for (int i = 0; i < size; i++) {
             final char c = s.charAt(i);
-            switch (c) {
-                case '%':
-                    i++;  // We can skip at least one char, e.g. `%%'.
-                    // Fall through.
-                case '+':
-                    modified = true;
-                    break;
+            if (c == '%' || c == '+') {
+                modified = true;
+                break;
             }
         }
         if (!modified) {