fix switch/case fallthrough

Signed-off-by: Tayou <git@tayou.org>

launcher/minecraft/mod/tasks/LocalTexturePackParseTask.cpp

@@ -186,6 +186,7 @@ bool processPackPNG(const TexturePack& pack)
             } else {
                 return png_invalid();  // pack.png does not exists or is not a valid file.
             }
+            return false;
         }
         case ResourceType::ZIPFILE: {
             Q_ASSERT(pack.type() == ResourceType::ZIPFILE);
@@ -215,6 +216,7 @@ bool processPackPNG(const TexturePack& pack)
                 zip.close();
                 return png_invalid();  // could not set pack.mcmeta as current file.
             }
+            return false;
         }
         default:
             qWarning() << "Invalid type for resource pack parse task!";