gf-server.cabal: Change the default for the flag fastcgi to False

If you want the fastcgi server, use cabal install -ffastcgi.

This is to avoid problems when you only want to compile pgf-http and the
fastcgi library fails to install, which it usually does, since it depends on
a C library which is not installed automatically with cabal.

src/server/gf-server.cabal

@@ -8,7 +8,7 @@ synopsis: FastCGI Server for Grammatical Framework
 
 flag fastcgi
   Description: Build the fcgi services (requires the fastcgi package)
-  Default:     True
+  Default:     False
 
 executable pgf-http
   main-is: pgf-http.hs