MSYS2 is not detected

[Cerber-Ursi]

Steps to reproduce:

• Install MSYS2 manually via its installer to some non-standard location.
• Run ridk install.

Expected behavior: it detects MSYS2 installation and runs correctly.
Actual behavior: it thinks that MSYS is not available.

The possible root of the problem is the detection algorithm, namely the way code scans for the relevant registry entry: this line searches using the regexp /^MSYS2 / (note the space), but the real DisplayName value is MSYS2 without space. After I manually changed DisplayName to MSYS2 something, ridk install seemed to work correctly.