Fix error from the previous commit

Author: ratajs

lib/AdvDiv.dart

@@ -47,11 +47,11 @@ String? advdiv(String n1, String n2, [final String minstr = "-", final String de
 
 	r1 = n1.contains(rstr1) ? (RegExp(RegExp.escape(rstr1)+r'(.+)'+RegExp.escape(rstr2)).firstMatch(n1.substring(n1.indexOf(".") + 1))?[1] ?? "0") : "0";
 	if(r1!="0")
-		n1 = n1.substring(0, n1.indexOf(".") + n1.substring(n1.indexOf(".") + 1).indexOf(rstr1));
+		n1 = n1.substring(0, n1.indexOf(".") + n1.substring(n1.indexOf(".") + 1).indexOf(rstr1) + 1);
 	n1 = n1.replaceFirst(RegExp(r'^0+'), "0").replaceFirst(RegExp(r1=="0" ? r'\.0*$' : r'\.$'), "");
 	r2 = n2.contains(rstr1) ? (RegExp(RegExp.escape(rstr1)+r'(.+)'+RegExp.escape(rstr2)).firstMatch(n2.substring(n2.indexOf(".") + 1))?[1] ?? "0") : "0";
 	if(r2!="0")
-		n2 = n2.substring(0, n2.indexOf(".") + n2.substring(n2.indexOf(".") + 1).indexOf(rstr1));
+		n2 = n2.substring(0, n2.indexOf(".") + n2.substring(n2.indexOf(".") + 1).indexOf(rstr1) + 1);
 	n2 = n2.replaceFirst(RegExp(r'^0+'), "0").replaceFirst(RegExp(r2=="0" ? r'\.0*$' : r'\.$'), "");