Add setReadOnly() to CopyableLabel

Added setReadOnly() so the TextBox can be made non-editable.

Change-Id: Ic9418e120264352d17e27d0c9a428918b7abc1c1
diff --git a/gerrit-gwtexpui/src/main/java/com/google/gwtexpui/clippy/client/CopyableLabel.java b/gerrit-gwtexpui/src/main/java/com/google/gwtexpui/clippy/client/CopyableLabel.java
index a9296eb..3e3a365 100644
--- a/gerrit-gwtexpui/src/main/java/com/google/gwtexpui/clippy/client/CopyableLabel.java
+++ b/gerrit-gwtexpui/src/main/java/com/google/gwtexpui/clippy/client/CopyableLabel.java
@@ -178,6 +178,7 @@
       textBox = new TextBox();
       textBox.setText(getText());
       textBox.setVisibleLength(visibleLen);
+      textBox.setReadOnly(true);
       textBox.addKeyPressHandler(new KeyPressHandler() {
         @Override
         public void onKeyPress(final KeyPressEvent event) {