Update src/utils/sqrt.rs

Co-authored-by: Shuhui Luo <[email protected]>

src/utils/sqrt.rs

@@ -11,7 +11,7 @@ use crate::prelude::*;
 pub fn sqrt(value: &BigInt) -> Result<BigInt, Error> {
     if !value >= Zero::zero() {
         return Err(Error::Incorrect(
-            "value has to be greater than -1".to_string(),
+            "value cannot be negative".to_string(),
         ));
     }