Fix a typo in changes/bug5916

changes/bug5916

@@ -2,5 +2,5 @@
     - Fix a memory leak when trying to launch a DNS request when the
       network is disabled or the nameservers are unconfigurable.  Fix
       for bug 5916; bugfix on Tor 0.1.2.1-alpha (for the
-      unconfigurable namesrever case) and on 0.2.3.9-alpha (for the
+      unconfigurable nameserver case) and on 0.2.3.9-alpha (for the
       DisableNetwork case).