remove the useless "dont ask again" checkbox

it is not checked anywhere => the dialog will appear no matter if the
checkbox was selected.

platform/dvcs-impl/src/com/intellij/dvcs/branch/DvcsTaskHandler.java

@@ -19,7 +19,6 @@ import com.intellij.dvcs.repo.AbstractRepositoryManager;
 import com.intellij.dvcs.repo.Repository;
 import com.intellij.openapi.application.ApplicationManager;
 import com.intellij.openapi.project.Project;
-import com.intellij.openapi.ui.DialogWrapper;
 import com.intellij.openapi.ui.Messages;
 import com.intellij.openapi.util.Condition;
 import com.intellij.openapi.util.text.StringUtil;
@@ -69,7 +68,7 @@ public abstract class DvcsTaskHandler<R extends Repository> extends VcsTaskHandl
                               StringUtil.join(problems, "<br>") + ".<br>" +
                               "Do you want to checkout existing " + myBranchType + "?", StringUtil.capitalize(myBranchType) + " Already Exists",
                               new String[]{Messages.YES_BUTTON, Messages.NO_BUTTON}, 0,
-                              Messages.getWarningIcon(), new DialogWrapper.PropertyDoNotAskOption("git.checkout.existing.branch")) == 0) {
+                              Messages.getWarningIcon()) == 0) {
         checkout(taskName, problems, null);
         map.addAll(problems);
       }