fix RADIUS support pillar

vyos.conf.j2

@@ -1515,7 +1515,7 @@ system {
         }
         {% endfor %}
         {% if 'source-address' in salt['pillar.get']('radius',{}) %}
-        radius-source-address {{ pillar['radius:source-address'] }}
+        radius-source-address {{ salt['pillar.get']('radius:source-address') }}
         {% endif %}
         {% else %}
         radius {
@@ -1524,7 +1524,7 @@ system {
                 key {{ server_data.get('key',server_data.get('secret','')) }}
             }
             {% endfor %}
-            source-address {{ pillar['radius:source-address'] }}
+            source-address {{ salt['pillar.get']('radius:source-address') }}
         }
         {% endif %}
         {% endif %}