Compile.sh: add warning without webserver

To avoid forcing people to have npm installed to build, and as
the webserver is not the heart of the app, a warning is added at
the end the build to remind the person compiling that the
webserver is missing if it wasn't built previously.

buildsystem/compile.sh

@@ -373,6 +373,10 @@ else
     fi
 fi
 
+if [ ! -d "./buildsystem/network-sharing-server/dist" ] ; then
+    echo "\033[1;32mWARNING: This was built without the webserver at ./buildsystem/network-sharing-server/dist ..."
+fi
+
 #######
 # RUN #
 #######