[2.7] bpo-1104: msilib.SummaryInfo.GetProperty() truncates the string by one character (GH-4517) (GH-11749)



Add one char to MsiSummaryInfoGetProperty() output
Based on the patch in [bpo-1104](https://bugs.python.org/issue1104) by Anthony Tuininga (atuining) and Mark McMahon (markm)
(cherry picked from commit 2de576e1)
Co-authored-by: Tzu-ping Chung <uranusjr@gmail.com>





https://bugs.python.org/issue1104