add license header

Author: khushijain21

testing/proxytest/https.go

@@ -6,7 +6,7 @@
 // not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
-//	http://www.apache.org/licenses/LICENSE-2.0
+//     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing,
 // software distributed under the License is distributed on an