claws-mail: fix conflict with shared_mime_info link

Fixes #10156. Close #10157.

pkgs/applications/networking/mailreaders/claws-mail/default.nix

···
     license = licenses.gpl3;
     platforms = platforms.linux;
     maintainers = [ maintainers.khumba ];
+    priority = 10;  # Resolve the conflict with the share/mime link we create.
   };
 
   src = fetchurl {