Delete unused code to fix warnings

Change-Id: Ie4f9d53c5035f19aea16d40a0f2170a7c9b5dd8c

gerrit-gwtui/src/main/java/com/google/gerrit/client/Gerrit.java

@@ -35,7 +35,6 @@ import com.google.gerrit.reviewdb.Account;
 import com.google.gerrit.reviewdb.AccountDiffPreference;
 import com.google.gerrit.reviewdb.AccountGeneralPreferences;
 import com.google.gerrit.reviewdb.AuthType;
-import com.google.gerrit.reviewdb.Patch;
 import com.google.gwt.core.client.EntryPoint;
 import com.google.gwt.core.client.GWT;
 import com.google.gwt.core.client.JavaScriptObject;

gerrit-httpd/src/main/java/com/google/gerrit/httpd/rpc/changedetail/SubmitAction.java

@@ -85,7 +85,6 @@ class SubmitAction extends Handler<ChangeDetail> {
         return changeDetailFactory.create(changeId).call();
 
       case NOT_READY: {
-        StringBuilder msg = new StringBuilder();
         for (SubmitRecord.Label lbl : result.get(0).labels) {
           switch (lbl.status) {
             case OK:

gerrit-server/src/test/java/com/google/gerrit/server/schema/SchemaCreatorTest.java

@@ -17,7 +17,6 @@ package com.google.gerrit.server.schema;
 import com.google.gerrit.reviewdb.ApprovalCategory;
 import com.google.gerrit.reviewdb.ApprovalCategoryValue;
 import com.google.gerrit.reviewdb.ReviewDb;
-import com.google.gerrit.reviewdb.SystemConfig;
 import com.google.gerrit.testutil.InMemoryDatabase;
 import com.google.gwtorm.client.OrmException;
 import com.google.gwtorm.jdbc.JdbcSchema;

gerrit-sshd/src/main/java/com/google/gerrit/sshd/commands/ShowCaches.java

@@ -241,7 +241,6 @@ final class ShowCaches extends CacheCommand {
     long now = System.currentTimeMillis();
     Collection<IoSession> list = acceptor.getManagedSessions().values();
     long oldest = now;
-    double writeThroughput = 0.0;
     for (IoSession s : list) {
       oldest = Math.min(oldest, s.getCreationTime());
     }