not commiting changelogs in jenkins without changes :-)

build.gradle

@@ -107,6 +107,9 @@ task changelog << {
 	}
 	fileChangelog.delete()
 
+	def nameUserCI = 'Jenkins'
+	def lastCommitByCI = false
+
 	def builder
 	def commits;
 	def numTags = tags.size()
@@ -127,8 +130,12 @@ task changelog << {
 			}
 		}
 
+		if (commits != null && nameUserCI.equalsIgnoreCase(commits[0].committer.name)) {
+			lastCommitByCI = true
+		}
+
 		commits.grep { commit -> 
-			!'jenkins'.equalsIgnoreCase(commit.committer.name)
+			!nameUserCI.equalsIgnoreCase(commit.committer.name)
 		}.inject(builder) { bldr, commit ->
 			bldr.append('  - ')
 			bldr.append(commit.shortMessage)
@@ -139,7 +146,9 @@ task changelog << {
 	    fileChangelog << builder.toString()
 	}
 
-	grgit.commit(message: 'Updating changelog', amend: false)
+	if (!lastCommitByCI) {
+		grgit.commit(message: 'Updating changelog', amend: false)
+	}
 }
 
 task vagrantExport(type: Zip) {