databases/mongodb42: Update to 4.2.10

• Update mongodb42 and mongodb42-tools to 4.2.10
• Update CONFLICTS_INSTALL. (mongodb44-tools will never exist, but became mongodb-tools)

Changelog:

https://docs.mongodb.com/manual/release-notes/4.2/#oct-2-2020

PR: 250157
Submitted by: Ronald Klop (maintainer)