Fix single line `end-pr` and `end-ds` syntax highlighting error

[barrettotte]

The end keyword of single line declarations of dcl-pr and dcl-ds seem to have broken at some point.

Sample from tests/issues/29.rpgle

dcl-pr main extpgm('TESTR') end-pr;

Sample from tests/issues/115.rpgle

dcl-ds prtDs len(132) end-ds;

Probably some convoluted regex problem I broke without looking through prior samples. I'll fix this while fixing a couple other reported issues.

[chrjorgensen]

@barrettotte Nice having you back! 😃