(Maint) Handle NoMethodError on 2003

Commit b5a4c68f1 modified the operatingsystemrelease fact to return more
meaningful Windows versions, e.g. 2003 instead of the kernelrelease fact
value, 5.2.3790. However, on (some?) non-R2 versions of 2003, the
othertypedescription method is not available on the WMI class
Win32_OperatingSystem[1].

As a result, facter would output to stderr the following message:

    Could not retrieve operatingsystemrelease: unknown property or method:
    `othertypedescription'
      HRESULT error code:0x80020006
        Unknown name.

This commit simply rescues the NoMethodError and outputs 2003.