Revert "Fix getting stack ip for heatclient > 1.5.1"

We need to bump heatclient version on CI to at least Mitaka
(1.1.1) first.

This reverts commit 23df6761a0f2cfe4d1287a525e472c9a8c6c5368.

Change-Id: Ifba27ffea965ee093ace4265a2520fd512dad973
diff --git a/src/com/mirantis/mk/Openstack.groovy b/src/com/mirantis/mk/Openstack.groovy
index fdaf014..8236ff3 100644
--- a/src/com/mirantis/mk/Openstack.groovy
+++ b/src/com/mirantis/mk/Openstack.groovy
@@ -264,10 +264,10 @@
  * @param path         Optional path to the custom virtualenv
  */
 def getHeatStackOutputParam(env, name, outputParam, path = null) {
-    cmd = "openstack stack output show ${name} ${outputParam} -f value -c output_value"
+    cmd = "heat output-show ${name} ${outputParam}"
     output = runOpenstackCommand(cmd, env, path)
     echo("${cmd}: ${output}")
-    return "${output}"
+    return "${output}".substring(1, output.length()-1)
 }
 
 /**