merged the flathub changes here

.gitmodules

@@ -1,3 +0,0 @@
-[submodule "shared-modules"]
-	path = shared-modules
-	url = https://github.com/flathub/shared-modules

sh.popcorntime.PopcornTime.appdata.xml

@@ -1,7 +1,8 @@
 <!-- Copyright 2018 Ströger Florian -->
 <?xml version="1.0" encoding="UTF-8"?>
 <component type="desktop">
-  <id>sh.popcorntime.PopcornTime.desktop</id>
+  <id>sh.popcorntime.PopcornTime</id>
+  <launchable type="sh.popcorntime.PopcornTime.desktop"/>
   <metadata_license>CC0-1.0</metadata_license>
   <project_license>GPL-3.0</project_license>
   <name>PopcornTime</name>

sh.popcorntime.PopcornTime.yml

@@ -3,8 +3,8 @@ runtime: org.freedesktop.Platform
 runtime-version: '18.08'
 branch: stable
 sdk: org.freedesktop.Sdk
-base: org.electronjs.Electron2.BaseApp
-base-version: stable
+base: io.atom.electron.BaseApp
+base-version: '18.08'
 command: popcorntime-wrapper
 separate-locales: false
 finish-args:
@@ -15,7 +15,6 @@ finish-args:
 - --filesystem=home:ro
 - --talk-name=org.freedesktop.Notifications
 modules:
-- shared-modules/gtk2/gtk2.json
 - name: popcorntime
   buildsystem: simple
   cleanup: