Fix yy_setBaselineOffset not work issue.

Ref: ibireme#914

Author: yanyin1986

YYText/Utility/NSAttributedString+YYText.m

@@ -1056,7 +1056,11 @@ - (void)yy_setExpansion:(NSNumber *)expansion range:(NSRange)range {
 
 - (void)yy_setBaselineOffset:(NSNumber *)baselineOffset range:(NSRange)range {
     if (kSystemVersion >= 7) {
+#if __IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_11_0
+        [self yy_setAttribute:(NSString *)kCTBaselineOffsetAttributeName value:baselineOffset range:range];
+#else
         [self yy_setAttribute:NSBaselineOffsetAttributeName value:baselineOffset range:range];
+#endif
     }
 }