vim: lhp syntax: quotation regex revert for single quotes
vim: lhp syntax: quotation regex revert for single quotes

This undoes the changes from the two commits below, to make the syntax
regex
follow the older, original regex code. This is because the older code is
smarter in disregarding apostrophes.

2d3a665077daad00538fb20ebb3daa4d9f1c7b9c
83d61a6c6de61dbd7fad2f84ffd1a94a084c2e7f

The double quotation mark regex are left as-is, since a double quotation
` " ' character is never used ambiguously.

listx/syscfg,listx/syscfg,listx/syscfg,listx/syscfg,listx/syscfg