Fix problem with background style appearing after last character on line.
Fix problem with background style appearing after last character on line.

windoze/scintilla,windoze/scintilla,keperlia/foo-wsh-panel-mod.scintilla,windoze/scintilla,windoze/scintilla,keperlia/foo-wsh-panel-mod.scintilla,keperlia/foo-wsh-panel-mod.scintilla,windoze/scintilla,keperlia/foo-wsh-panel-mod.scintilla,keperlia/foo-wsh-panel-mod.scintilla,keperlia/foo-wsh-panel-mod.scintilla,windoze/scintilla,windoze/scintilla,windoze/scintilla