Improved setting error messages to jenkins job descriptions

Change-Id: Ia19224b7334d6fd468ecc40be87d5b4df795adc5
diff --git a/build-debian-packages-jmx-exporter.groovy b/build-debian-packages-jmx-exporter.groovy
index b4e9760..71f626e 100644
--- a/build-debian-packages-jmx-exporter.groovy
+++ b/build-debian-packages-jmx-exporter.groovy
@@ -69,7 +69,7 @@
     } catch (Throwable e) {
        // If there was an 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"])