Fix missing bracket

Change-Id: I0cba66378367174c6f918aa3452b8f65e742723b
diff --git a/test-salt-models-pipeline.groovy b/test-salt-models-pipeline.groovy
index 1928e4c..0824db4 100644
--- a/test-salt-models-pipeline.groovy
+++ b/test-salt-models-pipeline.groovy
@@ -10,7 +10,7 @@
           credentialsId : CREDENTIALS_ID
       ])
 
-      if (fileExists('classes/system') {
+      if (fileExists('classes/system')) {
         ssh.prepareSshAgentKey(CREDENTIALS_ID)
         dir('classes/system') {
           remoteUrl = git.getGitRemote()