Bug#1026421: Bug #1026421 rclone should have a build dependency on golang >= 1.17

[Drew Parsons]

severity 1026421 important
thanks

The version of rclone in testing is not directly intended to be built on 
stable, hence this bug is not Severity: serious (it builds fine in 
unstable and testing).

Severity: serious is intended to mark packages which are not fit for 
release in testing (the future stable release).