org.gnome.Calendar.json: removed comments

Currently this json file contains comments in C-style.

However, comments in json files are not allowed and they could
break external programs that make use of them.

To fix it, I removed any comment from org.gnome.Calendar.json file.

https://bugzilla.gnome.org/show_bug.cgi?id=781787

org.gnome.Calendar.json

@@ -7,19 +7,14 @@
     "tags": ["devel"],
     "desktop-file-name-prefix": "(Development) ",
     "finish-args": [
-        /* X11 + XShm access */
         "--share=ipc", "--socket=x11",
-        /* Wayland access */
         "--socket=wayland",
-        /* Needs to talk to the network: */
         "--share=network",
-        /* Evolution data server access */
         "--talk-name=org.gnome.OnlineAccounts",
         "--talk-name=org.gnome.evolution.dataserver.AddressBook9",
         "--talk-name=org.gnome.evolution.dataserver.Calendar7",
         "--talk-name=org.gnome.evolution.dataserver.Sources5",
         "--talk-name=org.gnome.evolution.dataserver.Subprocess.Backend.*",
-        /* Needed for dconf to work */
         "--filesystem=xdg-run/dconf", "--filesystem=~/.config/dconf:ro",
         "--talk-name=ca.desrt.dconf", "--env=DCONF_USER_CONFIG_DIR=.config/dconf"
     ],