Disable inflate gzip on head method (#7432)

app/lib/request.rb

@@ -51,7 +51,7 @@ class Request
   end
 
   def headers
-    (@account ? @headers.merge('Signature' => signature) : @headers).reverse_merge('Accept-Encoding' => 'gzip').without(REQUEST_TARGET)
+    (@account ? @headers.merge('Signature' => signature) : @headers).without(REQUEST_TARGET)
   end
 
   private
@@ -61,6 +61,7 @@ class Request
     @headers['User-Agent']      = user_agent
     @headers['Host']            = @url.host
     @headers['Date']            = Time.now.utc.httpdate
+    @headers['Accept-Encoding'] = 'gzip' if @verb != :head
   end
 
   def set_digest!