[artifactory.upload] Fix findFiles call

    findFiles step does not support absolute paths

    Related: RE-3241
    Related: PRODX-54274

Change-Id: Ic2d5930818d000a35edf20b62c6a5b23f14754a3
diff --git a/vars/artifactory.groovy b/vars/artifactory.groovy
index 4c5447c..0d443d6 100644
--- a/vars/artifactory.groovy
+++ b/vars/artifactory.groovy
@@ -128,7 +128,7 @@
 
         List targetFiles = []
         try {
-            targetFiles = findFiles(glob: specItem.pattern)
+            targetFiles = findFiles(glob: specItem.pattern.replaceFirst("^${env.WORKSPACE}/?", ""))
                 .findAll{ !it.directory }
                 .collect{ it.path }
         } catch (Exception e) {