Update npm-mongo dependency.

Thanks to filipenevola.

.meteor/versions

@@ -126,7 +126,7 @@ mquandalle:moment@1.0.1
 mquandalle:mousetrap-bindglobal@0.0.1
 msavin:usercache@1.8.0
 npm-bcrypt@0.9.3
-npm-mongo@3.8.0
+npm-mongo@3.8.1
 oauth@1.3.0
 oauth2@1.3.0
 observe-sequence@1.0.16