使用特殊文本时，YYLabel会有一长串的空格

[mythkiven]

代码与效果，见图片：

[mythkiven]

code:

NSMutableAttributedString *attString = [NSMutableAttributedString new];
    UIFont *font = [UIFont systemFontOfSize:16];
    NSString *string = @"ޙޓゝ₯";
    [attString appendAttributedString:[[NSAttributedString alloc] initWithString:string attributes:nil]];
    attString.yy_font = font;
    YYLabel * yylabel = [YYLabel new];
    yylabel.textVerticalAlignment = YYTextVerticalAlignmentTop;
    yylabel.textAlignment = NSTextAlignmentLeft;
    yylabel.backgroundColor = [UIColor cyanColor];
    yylabel.frame = CGRectMake(100, 200, 210, 30);
    yylabel.attributedText = attString;
    [self.view addSubview:yylabel];