Fix incorrect fontconfig.

config/fontconfig/45-Hack.conf

@@ -9,10 +9,10 @@
   <!-- if this file is put in user’s configuration, unset sans-serif family -->
   <match>
     <test compare="eq" name="family">
-        <string>Hack</string>
+        <string>sans-serif</string>
     </test>
     <test compare="eq" name="family">
-        <string>sans-serif</string>
+        <string>Hack</string>
     </test>
     <edit mode="delete" name="family"/>
   </match>