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

rhaberkorn/scintilla-mirror,rhaberkorn/scintilla-mirror,rhaberkorn/scintilla-mirror,rhaberkorn/scintilla-mirror,rhaberkorn/scintilla-mirror,rhaberkorn/scintilla-mirror,rhaberkorn/scintilla-mirror,rhaberkorn/scintilla-mirror