Improved setting error messages to jenkins job descriptions

Change-Id: Ia19224b7334d6fd468ecc40be87d5b4df795adc5
diff --git a/aptly-promote-pipeline.groovy b/aptly-promote-pipeline.groovy
index e5d9743..eb10f40 100644
--- a/aptly-promote-pipeline.groovy
+++ b/aptly-promote-pipeline.groovy
@@ -26,9 +26,9 @@
   } catch (Throwable e) {
      // If there was an error or exception thrown, the build failed
      currentBuild.result = "FAILURE"
-     currentBuild.description = e.message
+     currentBuild.description = currentBuild.description ? e.message + " " + currentBuild.description : e.message
      throw e
   } finally {
      common.sendNotification(currentBuild.result,"",["slack"])
   }
-}
\ No newline at end of file
+}