add unit test for initial creating tenant without security context

Signed-off-by: Michael Hirsch <michael.hirsch@bosch-si.com>

hawkbit-repository/hawkbit-repository-test/src/main/java/org/eclipse/hawkbit/repository/test/util/WithSpringAuthorityRule.java

@@ -63,7 +63,7 @@ public class WithSpringAuthorityRule implements TestRule {
         }
         return oldContext;
     }
-
+    
     /**
      * @param annotation
      */
@@ -129,6 +129,14 @@ public class WithSpringAuthorityRule implements TestRule {
     private void after(final SecurityContext oldContext) {
         SecurityContextHolder.setContext(oldContext);
     }
+    
+    /**
+     * Clears the current security context.
+     */
+    public void clear()
+    {
+        SecurityContextHolder.clearContext();
+    }
 
     /**
      * @param callable