Fix typo in OMEC license check manual run

Change-Id: I3830ed309148545ff56a2cf7b39a30a0c36bcce2
diff --git a/jjb/pipeline/omec-reuse-scan.groovy b/jjb/pipeline/omec-reuse-scan.groovy
index 9db0c9c..605f285 100644
--- a/jjb/pipeline/omec-reuse-scan.groovy
+++ b/jjb/pipeline/omec-reuse-scan.groovy
@@ -70,7 +70,7 @@
                     #!/usr/bin/env bash
 
                     cd ${params.project}
-                    if [ ! -Z ${params.ghprbPullId} ]
+                    if [ ! -z ${params.ghprbPullId} ]
                     then
                       git checkout FETCH_HEAD
                     else