While submitting an update for sle-module-toolchain-release package, errors
were detected by the maintenance checker script.  It turned out to be a result
of /usr/lib/obs/service/source_validators/20-files-present-and-referenced
failing to process the special .spec file.

How to reproduce:
# osc -A https://api.suse.de/ co Devel:Toolchain:SLE12
_product:sle-module-toolchain-release
# cd Devel\:Toolchain\:SLE12/_product\:sle-module-toolchain-release/
# /usr/lib/obs/service/source_validators/20-files-present-and-referenced

Actual output:
# /usr/lib/obs/service/source_validators/20-files-present-and-referenced
(E) warning: mentioned in spec file does not exist.
(E) line mentioned in spec file does not exist.
(E) 20: mentioned in spec file does not exist.
(E) Invalid mentioned in spec file does not exist.
(E) version mentioned in spec file does not exist.
(E) (double mentioned in spec file does not exist.
(E) separator mentioned in spec file does not exist.
(E) '-'): mentioned in spec file does not exist.
(E) sle-module-toolchain: mentioned in spec file does not exist.
(E) Provides: mentioned in spec file does not exist.
(E) product() mentioned in spec file does not exist.
(E) = mentioned in spec file does not exist.
(E) sle-module-toolchain mentioned in spec file does not exist.

Expected output:
Exit status 0, nothing reported.

Interestingly enough, the script works fine on SLE 11 SP4, which has bash
3.2.57.  It is failing on distros with bash 4.3.x and higher (SLE 12, Leap 42,
Tumbleweed).