Wrong museScore version tag written when using "-t" option

Ubuntu 14.04, GIT commit: 93d1b48

See #61781: User offset on slur applied incorrectly on save/load. A bit of a wild goose chase that eventually led me to discover the following:

1) start MuseScore with "-t" option
2) save a score in MSCX format
3) open in text editor

Result: museScore version tag reads "2.00" rather than the actual current version, "2.06". As a result, code that depends on format changes made over the past few months does not work correctly (thus leading to the issue referenced above).

I guess the idea was to make the version information less volatile when creating mtests, but I don't think we can get away with this.