Did not check the correct string

Co-authored-by: r3cp3ct <45179536+r3cp3ct@users.noreply.github.com>
Co-authored-by: sigonasr2 <sigonasr2@gmail.com>

src/sig/engine/String.java

@@ -95,7 +95,7 @@ public class String{
     public String replace(int start,int end,java.lang.String str) {
         this.sb.replace(start,end,str);
         bounds = new Point(0,1);
-        updateBounds(str);
+        updateBounds(this.sb.toString());
         return this;
     }
     public int length() {