Fix 2019-08-04 regex lint

Fix 2019-08-04 regex lint

Problem reported by Mattias Engdegård in:
https://lists.gnu.org/r/emacs-devel/2019-08/msg00085.html
* lisp/calendar/diary-lib.el (diary-glob-file-regexp-prefix):
Omit unnecessary ‘\’ before ordinary char.
* lisp/cedet/inversion.el (inversion-decoders):
* lisp/org/ob-haskell.el (org-babel-haskell-export-to-lhs):
Omit unnecessary ‘?’ after nullable pattern.
* lisp/org/org-capture.el (org-capture-fill-template):
Match upper-case as well as lower-case letters.
* lisp/progmodes/cc-mode.el (c-before-change-check-unbalanced-strings)
(c-after-change-mark-abnormal-strings):
Simplify ‘.|\r’ to ‘.’.
* lisp/progmodes/gdb-mi.el (gdb-jsonify-buffer):
Put ‘-’ at end of bracket expression.