Old documentation isn't removed after upgrading Qt and QtC

Today I have upgraded Qt (5.5.0 -> 5.5.1) and QtC (3.5.0 -> 3.5.1) via maintenance tool. QtC automatically added the documentation of Qt and QtC with new versions to the docs list in the Help view.

However, there were 2 sets of Qt 5.5.1 and QtC 3.5.1 documents in the docs list of the Help view. When I checked Preferences -> Help -> Documentation, there were "auto-detected" documentations for Qt 5.5.0 and Qt 5.5.1.

After removing 5.5.0 ones manually, the Help view listed only a single set help documents.

It seems that QtC is good at finding new documentation but not so at removing the old ones. As you most probably know, when Qt is upgraded (such as 5.5.0 -> .1) documentation files are upgraded in place. I guess QtC should verify that previously detected documentation still has the same version data in its manifest file.