Revert "Allow to enable git protocol version 2 for upload pack"

The JGit implementation of protocol V2 does not invoke the
advertiseRefsHook on fetch and ls-refs, which results in all
refs being sent.

This reverts commit 437d7ef616.

Change-Id: Ia9f0c6140649db2c638ab0483fd14aad99152ff9

java/com/google/gerrit/server/git/TransferConfig.java

@@ -29,7 +29,6 @@ public class TransferConfig {
   private final long maxObjectSizeLimit;
   private final String maxObjectSizeLimitFormatted;
   private final boolean inheritProjectMaxObjectSizeLimit;
-  private final boolean enableProtocolV2;
 
   @Inject
   TransferConfig(@GerritServerConfig Config cfg) {
@@ -46,7 +45,6 @@ public class TransferConfig {
     maxObjectSizeLimitFormatted = cfg.getString("receive", null, "maxObjectSizeLimit");
     inheritProjectMaxObjectSizeLimit =
         cfg.getBoolean("receive", "inheritProjectMaxObjectSizeLimit", false);
-    enableProtocolV2 = cfg.getBoolean("receive", "enableProtocolV2", false);
 
     packConfig = new PackConfig();
     packConfig.setDeltaCompress(false);
@@ -74,8 +72,4 @@ public class TransferConfig {
   public boolean inheritProjectMaxObjectSizeLimit() {
     return inheritProjectMaxObjectSizeLimit;
   }
-
-  public boolean enableProtocolV2() {
-    return enableProtocolV2;
-  }
 }