#784: removed expired root certificate

 from ca root certificate store: certificate “DST Root CA X3” used by
Lets Encrypt

updated version string to "21.1"

#715: improved reporting for binding errors

 on Windows

#748: removed outdated links from web interface

 and merged Info and About tabs

#648: update license text

because of change of Free Software Foundation address but also includes
minor formatting changes.

updated version string to "21.0"

#629: added aarch64 binaries to Linux installer and Android installer

#612: better description of option UMask

#351: sleep longer in frontend when console window is hidden

(only in Windows app)

#538: android resolver workaround

isn’t necessary when building specifically for Android using Android
NDK.