Check that parameter is not empty when creating job

Change-Id: I67d97e1e501f3d983dfb2a78352e5da0a57af9a1
diff --git a/jenkins/files/jobs/_parameters.xml b/jenkins/files/jobs/_parameters.xml
index 0f63ad5..08fd728 100755
--- a/jenkins/files/jobs/_parameters.xml
+++ b/jenkins/files/jobs/_parameters.xml
@@ -18,7 +18,7 @@
             </a>
           </choices>
           {%- endif %}
-          {%- if param.default is defined %}
+          {%- if param.default is defined and param.default != '' %}
           <defaultValue>{{ param.get('default') }}</defaultValue>
           {%- else %}
           <defaultValue/>