gf.cabal: adjust version constrains on the network, cgi and httpd-shed packages

gf.cabal

@@ -53,6 +53,9 @@ flag interrupt
 flag server
   Description: Include --server mode
   Default:     True
+flag network-uri
+   description: Get Network.URI from the network-uri package
+   default: True
 
 --flag new-comp
 --  Description: Make -new-comp the default
@@ -263,11 +266,12 @@ Library
     cpp-options: -DC_RUNTIME
 
   if flag(server)
-    build-depends: httpd-shed>=0.4.0.2, network>=2.3 && <2.6, json
-    if impl(ghc>=7.8)
-      build-depends: cgi>=3001.2.2.0
+    build-depends: httpd-shed>=0.4.0.3, network>=2.3 && <2.7, json,
+                   cgi>=3001.2.2.0
+    if flag(network-uri)
+      build-depends: network-uri>=2.6, network>=2.6
     else
-      build-depends: cgi
+      build-depends: network<2.6
 
     cpp-options: -DSERVER_MODE
     other-modules: