NEXUS-6242: Backport to Nexus 2.7.x

How parser is looked up, one change from this commit
https://github.com/sonatype/nexus-oss/commit/7cab8b575936a521889ddf194ac34187a78a6031#diff-0
NEXUS-6242: Backport to Nexus 2.7.x

Commit
95f212c2e946dd6d6f9c8a1a1671ee180bd78d0d
Merge pull request #332 from sonatype/nexus-2.7.x-NEXUS-6242

[2.7.x] NEXUS-6242: Backport to Nexus 2.7.x

merging based on +1s