Fix typo (thanks Gerard)

git-svn-id: https://humgenprojects.lumc.nl/svn/mutalyzer/trunk@659 eb6bd6ab-9ccd-42b9-aceb-e2899b4a52f1

mutalyzer/templates/help.html

@@ -63,7 +63,7 @@
           with the Name checker
       </p>
       <p>
-        - <a href="#GenBankUploader">Refrence File Loader</a>: allows you to
+        - <a href="#GenBankUploader">Reference File Loader</a>: allows you to
           upload and use your own reference sequence.
       </p>
       <p>