Fix typo in expires.conf

Close #82.

h5bp/location/expires.conf

@@ -2,7 +2,7 @@
 
 # No default expire rule. This config mirrors that of apache as outlined in the
 # html5-boilerplate .htaccess file. However, nginx applies rules by location,
-# the apache rules are defined by type. A concequence of this difference is that
+# the apache rules are defined by type. A consequence of this difference is that
 # if you use no file extension in the url and serve html, with apache you get an
 # expire time of 0s, with nginx you'd get an expire header of one month in the
 # future (if the default expire rule is 1 month). Therefore, do not use a