v5.3.1-rc.1

Full Changelog

• Adapt release script for riot-desktop
  #1319
• Fix: prevent spurious notifications from indexer
  #1318
• Always create our own user object
  #1317
• Fix incorrect backup key format in SSSS
  #1311
• Fix e2ee crash after refreshing after having received a cross-singing key
  reset
  #1315
• Fix: catch send errors in SAS verifier
  #1314
• Clear cross-signing keys when detecting the keys have changed
  #1312
• Upgrade deps
  #1310