src:request-tracker5: ftbfs due to changes in gpg error messages

Imported from Debian bug http://bugs.debian.org/988905:

Package: src:request-tracker5
Version: 5.0.1+dfsg-1
Severity: serious
Tags: ftbfs
Justification: fails to build from source

Dear Maintainer,

As can be seen at

https://tests.reproducible-builds.org/debian/rb-pkg/unstable/amd64/request-tracker5.html

or

https://launchpad.net/ubuntu/+source/request-tracker5/5.0.1+dfsg-1

the package fails to build with the current state of unstable / Ubuntu
impish.

The failures are:

# Failed test at t/mail/crypt-gnupg.t line 171.
# found warning: gpg: error retrieving '<email address hidden>' via WKD: Server indicated a failure
# expected to find warning: (?^:public key not found|error retrieving 'keyless\@example.com' via WKD: No data)

# Failed test at t/web/crypt-gnupg.t line 358.
# found warning: gpg: error retrieving '<email address hidden>' via WKD: Server indicated a failure
# found warning: Recipient '<email address hidden>' is unusable, the reason is 'No specific reason given'
# expected to find warning: (?^:nokey\@example.com: skipped: public key not found|error retrieving 'nokey\@example.com' via WKD: No data)
# expected to find warning: (?^:Recipient 'nokey\@example.com' is unusable)

# Failed test at t/web/crypt-gnupg.t line 380.
# found warning: gpg: error retrieving '<email address hidden>' via WKD: Server indicated a failure
# found warning: Recipient '<email address hidden>' is unusable, the reason is 'No specific reason given'
# expected to find warning: (?^:nokey\@example.com: skipped: public key not found|error retrieving 'nokey\@example.com' via WKD: No data)
# expected to find warning: (?^:Recipient 'nokey\@example.com' is unusable)

(the messages are actually slightly different in Ubuntu). This seems
pretty benign really and probably the tests should be relaxed?

Cheers,
mwh

-- System Information:
Debian Release: bullseye/sid
  APT prefers focal-updates
  APT policy: (500, 'focal-updates'), (500, 'focal-security'), (500, 'focal'), (400, 'focal-proposed'), (100, 'focal-backports')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 5.4.0-73-generic (SMP w/8 CPU cores)
Kernel taint flags: TAINT_PROPRIETARY_MODULE, TAINT_OOT_MODULE
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled