patch 8.1.0107: Python: getting buffer option clears message

Problem:    Python: getting buffer option clears message. (Jacob Niehus)
Solution:   Don't use aucmd_prepbuf(). (closes #3079)

src/option.c

@@ -9692,7 +9692,7 @@ get_option_value_strict(
	     * consider it set when 'ff' or 'fenc' changed. */
	    if (p->indir == PV_MOD)
	    {
		*numval = bufIsChanged((buf_T *) from);
		*numval = bufIsChanged((buf_T *)from);
		varp = NULL;
	    }
#ifdef FEAT_CRYPT
@@ -9705,17 +9705,21 @@ get_option_value_strict(
#endif
	    else
	    {
		aco_save_T	aco;
		aucmd_prepbuf(&aco, (buf_T *) from);
		buf_T *save_curbuf = curbuf;

		// only getting a pointer, no need to use aucmd_prepbuf()
		curbuf = (buf_T *)from;
		curwin->w_buffer = curbuf;
		varp = get_varp(p);
		aucmd_restbuf(&aco);
		curbuf = save_curbuf;
		curwin->w_buffer = curbuf;
	    }
	}
	else if (opt_type == SREQ_WIN)
	{
	    win_T	*save_curwin;
	    save_curwin = curwin;
	    curwin = (win_T *) from;
	    win_T	*save_curwin = curwin;

	    curwin = (win_T *)from;
	    curbuf = curwin->w_buffer;
	    varp = get_varp(p);
	    curwin = save_curwin;

src/version.c

@@ -789,6 +789,8 @@ static char *(features[]) =

static int included_patches[] =
{   /* Add new patch number below this line */
/**/
    107,
/**/
    106,
/**/