fix spelling

rocketchat-reporting

@@ -17,7 +17,7 @@ Time: {{ report.ts }}
 URL to message:
     If channel: {{ baseurl }}/channel/{{ report.message.rid }}?msg={{ report.message._id }}
     If group: {{ baseurl }}/group/{{ report.message.rid }}?msg={{ report.message._id }}
-    If dM: {{ baseurl }}/direct/{{ report.message.rid }}?msg={{ report.message._id }}
+    If dm: {{ baseurl }}/direct/{{ report.message.rid }}?msg={{ report.message._id }}
 
 -- description --
 {{ report.description|d("<none>")|indent(first=true) }}