make the code ready for pull request

Author: rozi26

src/main/java/com/thealgorithms/maths/ComplexNumberUtil.java

@@ -263,15 +263,4 @@ public static ComplexNumber arccot(ComplexNumber num) {
 
         return multiply(divide(MINUS_I, TWO), ln(divide(add(num, PLUS_I), subtract(num, PLUS_I))));
     }
-
-    public ComplexNumber add(ComplexNumber added)
-    {
-        return new ComplexNumber(1,1);
-    }
-
-    public static void main(String[] args)
-    {
-        ComplexNumber num1 = new ComplexNumber(1,1);
-        ComplexNumber num2 =  new ComplexNumber(2,3);
-    }
 }