Improved Jenkins plugin installing

Change-Id: Ie1f781c0a5d7c7fcffd7d763f7dde4fe3de2e872
diff --git a/_states/jenkins_plugin.py b/_states/jenkins_plugin.py
index 4956751..6c2b0d4 100644
--- a/_states/jenkins_plugin.py
+++ b/_states/jenkins_plugin.py
@@ -33,6 +33,9 @@
   }}
 }}else{{
     exists = true
+    if({restart}){{
+      instance.doSafeRestart()
+    }}
     print("EXISTS")
 }}
 if (installed) {{