Merge branch 'jk/sq-dequote-on-bogus-input'

Code to unquote single-quoted string (used in the parser for
configuration files, etc.) did not diagnose bogus input correctly
and produced bogus results instead.

* jk/sq-dequote-on-bogus-input:
  sq_dequote: fix extra consumption of source string

diff --cc quote.c
Simple merge

diff --cc t/t1300-repo-config.sh
Simple merge