GUI robot test code with latest directives

Changes:
     - Run Keyword If is deprecated since Robot
       Framework version 5.*, use 'IF' instead
     - Remove the keyword from teardown and add
       check in the keyword to re-run GUI if
       test failed.

Tested:
     - Tested with dry-run option changes

Change-Id: Ie1b0957470ac4a33c846aa153a0c776fdba34db5
Signed-off-by: George Keishing <gkeishin@in.ibm.com>
diff --git a/gui/lib/gui_resource.robot b/gui/lib/gui_resource.robot
index 5c13da7..96b9f13 100644
--- a/gui/lib/gui_resource.robot
+++ b/gui/lib/gui_resource.robot
@@ -198,8 +198,9 @@
     Click Button  ${xpath_add_dns_ip_address_button}
     Input Text  ${xpath_input_static_dns}  ${dns_server}
     Click Button  ${xpath_add_button}
-    Run keyword if  '${expected_status}' != 'Valid format'
-    ...  Run keywords  Page Should Contain  ${expected_status}  AND  Return From Keyword
+    IF  '${expected_status}' != 'Valid format'
+        Page Should Contain  ${expected_status}  AND  Return From Keyword
+    END
 
     Wait Until Page Contains Element  ${xpath_add_dns_ip_address_button}  timeout=10sec
     Wait Until Page Contains  ${dns_server}  timeout=40sec