fix(packages): Improve multi-paragraph pullquotes

This removes the stretched lines at the end of every paragraph but the
last, when a `pullquote` (from the `pullquote` package) contains several
paragraphs. It does not fix the bug mentioned in #865.

packages/pullquote.lua

@@ -36,7 +36,6 @@ SILE.registerCommand("pullquote", function (options, content)
   SILE.settings.temporarily(function ()
     SILE.settings.set("document.rskip", SILE.nodefactory.glue(setback))
     SILE.settings.set("document.lskip", SILE.nodefactory.glue(setback))
-    SILE.settings.set("typesetter.parfillskip", SILE.nodefactory.glue())
     SILE.settings.set("current.parindent", SILE.nodefactory.glue())
     SILE.call("pullquote:font")
     typesetMark(true, setback, scale, color, "“")