chore: tweak approot for port offset

stack.yaml.lock

@@ -40,13 +40,13 @@ packages:
 - completed:
     name: HaskellNet
     version: 0.5.1
-    git: git://github.com/jtdaugherty/HaskellNet.git
+    git: https://github.com/jtdaugherty/HaskellNet.git
     pantry-tree:
       size: 4011
       sha256: 921b437ef18ccb04f889301c407263d6b5b72c5864803a000b1e61328988ce70
     commit: 5aa1f3b009253b02c4822005ac59ee208a10a347
   original:
-    git: git://github.com/jtdaugherty/HaskellNet.git
+    git: https://github.com/jtdaugherty/HaskellNet.git
     commit: 5aa1f3b009253b02c4822005ac59ee208a10a347
 - completed:
     name: HaskellNet-SSL

start.sh

@@ -16,6 +16,7 @@ export COOKIES_SECURE=${COOKIES_SECURE:-false}
 export ALLOW_DEPRECATED=${ALLOW_DEPRECATED:-true}
 export ENCRYPT_ERRORS=${ENCRYPT_ERRORS:-false}
 export RIBBON=${RIBBON:-${__HOST:-localhost}}
+export APPROOT=${APPROOT:-http://localhost:$((${PORT_OFFSET:-0} + 3000))}
 unset HOST
 
 move-back() {