Remove getter test failing on my locale

My locale is not 'en', so Messages retrieve a different string, and I don't see the point for this getter test.

src/test/java/org/jenkinsci/plugins/oic/OicLogoutActionTest.java

@@ -16,11 +16,6 @@ public void init() {
         action = new OicLogoutAction();
     }
 
-    @Test
-    public void getDisplayName() {
-        assertEquals("Oic Logout", action.getDisplayName());
-    }
-
     @Test
     public void getIconFileName() {
         assertNull(action.getIconFileName());