[Misc] Fix CLIRR exclude for MetaDataBlock. Here's what happened:
- in 4.5.1 a new clone() returning Block was added to MetaDataBlock to fix XRENDERING-283. This didn't generate any backward incompatibility when comparing to 4.5
- in 5.0M1-SNAPSHOT the clone() return type was changed from Block to MetaDataBlock. This caused a backward incompatibility when comparing to 4.5.1. Note that there is no JIRA issue for this breaking change in 5.0M1-SNAPSHOT...