Allow Sandstorm to serve Wekan HTTP API

This is probably not a "whole" fix, but this may be a missing piece.

sandstorm-pkgdef.capnp

@@ -226,7 +226,7 @@ const pkgdef :Spk.PackageDefinition = (
         verbPhrase = (defaultText = "removed from card"),
       ), ],
     ),
-
+    apiPath = "/api",
     saveIdentityCaps = true,
   ),
 );