Fix minor quality flaws

server/sonar-server/src/main/java/org/sonar/server/dashboard/template/ProjectCustomDashboard.java

@@ -54,7 +54,7 @@ public final class ProjectCustomDashboard extends DashboardTemplate {
     return dashboard;
   }
 
-  private void addFirstColumn(Dashboard dashboard) {
+  private static void addFirstColumn(Dashboard dashboard) {
     dashboard.addWidget("size", 1);
     dashboard.addWidget("code_coverage", 1);
     dashboard.addWidget("duplications", 1);

sonar-core/src/main/java/org/sonar/core/issue/IssueUpdater.java

@@ -22,9 +22,7 @@ package org.sonar.core.issue;
 import com.google.common.base.Function;
 import com.google.common.base.Joiner;
 import com.google.common.base.Objects;
-import com.google.common.base.Preconditions;
 import com.google.common.base.Predicate;
-import com.google.common.base.Strings;
 import com.google.common.collect.Collections2;
 import com.google.common.collect.Sets;
 import java.util.Calendar;