BOOKKEEPER-939: Fix typo of bookkeeper merge pr script

There is typo of bk-merge-pr.py script on merging pr without a jira id.

Author: Sijie Guo <sijie@apache.org>

Reviewers: Matteo Merli <mmerli@apache.org>

Closes #53 from sijie/sijie/fix_merge_script
diff --git a/dev/bk-merge-pr.py b/dev/bk-merge-pr.py
index c3cda40..a3fd206 100755
--- a/dev/bk-merge-pr.py
+++ b/dev/bk-merge-pr.py
@@ -336,7 +336,7 @@
     jira_ids = re.findall("%s-[0-9]{3,6}" % CAPITALIZED_PROJECT_NAME, title)
 
     if len(jira_ids) == 0:
-        pritnf ("No JIRA issue found to update")
+        print "No JIRA issue found to update"
     for jira_id in jira_ids:
         resolve_jira_issue(merge_branches, comment, jira_id)