Make sure string is not empty before adding it to metadata.

[yangtj207]

Description

Please provide a detailed description of the changes this pull request introduces. If available, also link to a docdb link where the issue/change have been presented on/discussed.
Make sure string is not empty before adding it to metadata. This is to support non-production jobs.

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• Does this PR affect CAF data format? If so, please assign a CAF maintainer as additional reviewer.
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[absolution1]

looks good thanks

[kjplows]

trigger build

[FNALbuild]

✔️ CI build for LArSoft Succeeded on slf7 for e26:prof -- details available through the CI dashboard

[FNALbuild]

✔️ CI build for LArSoft Succeeded on slf7 for c14:prof -- details available through the CI dashboard

[FNALbuild]

❌ CI build for ICARUS Failed at phase build ICARUS on slf7 for c14:prof -- details available through the CI dashboard

🚨 For more details about the failed phase, check the build ICARUS phase logs

parent CI build details are available through the CI dashboard

[FNALbuild]

❌ CI build for SBND Failed at phase build SBND on slf7 for c14:prof -- details available through the CI dashboard

🚨 For more details about the failed phase, check the build SBND phase logs

parent CI build details are available through the CI dashboard

[FNALbuild]

⚠️ CI build for ICARUS Warning at phase ci_tests ICARUS on slf7 for e26:prof - ignored warnings for build -- details available through the CI dashboard

🚨 For more details about the warning phase, check the ci_tests ICARUS phase logs

parent CI build details are available through the CI dashboard

[FNALbuild]

⚠️ CI build for SBND Warning at phase ci_tests SBND on slf7 for e26:prof - ignored warnings for build -- details available through the CI dashboard

🚨 For more details about the warning phase, check the ci_tests SBND phase logs

parent CI build details are available through the CI dashboard