XEP-0374: Fix typo

xep-0374.xml

@@ -128,7 +128,7 @@
 
   <section2 topic='OpenPGP Secured Instant Messaging' anchor='openpgp-secured-im'>
 
-    <p>In order to establish a OpenPGP secured IM communication, IM
+    <p>In order to establish an OpenPGP secured IM communication, IM
     clients first need to determine the public key of their
     interlocutor(s). OpenPGP historically provides public keyservers
     which can be used for key retrieval. Additional there are methods