Simplify RE_COMMON_PLACEHOLDERS
Simplify RE_COMMON_PLACEHOLDERS

Use the \w shorthand for word characters group to make the regex shorter
and more readable. Remove superfluous capture groups.

alexhenrie/poedit,alexhenrie/poedit,vslavik/poedit,vslavik/poedit,vslavik/poedit,alexhenrie/poedit,alexhenrie/poedit,vslavik/poedit,alexhenrie/poedit,vslavik/poedit