Fix deprecation compile warning (#1154)

Signed-off-by: Patrik Stas <patrik.stas@absa.africa>

did_core/did_methods/did_resolver_sov/src/resolution/utils.rs

@@ -1,4 +1,4 @@
-use chrono::{DateTime, NaiveDateTime, Utc};
+use chrono::{DateTime, Utc};
 use did_resolver::{
     did_doc::schema::{
         did_doc::DidDocument,
@@ -50,8 +50,7 @@ fn get_txn_time_from_response(resp: &str) -> Result<i64, DidSovError> {
 }
 
 fn unix_to_datetime(posix_timestamp: i64) -> Option<DateTime<Utc>> {
-    NaiveDateTime::from_timestamp_opt(posix_timestamp, 0)
-        .map(|date_time| DateTime::<Utc>::from_naive_utc_and_offset(date_time, Utc))
+    DateTime::from_timestamp(posix_timestamp, 0)
 }
 
 pub(super) fn is_valid_sovrin_did_id(id: &str) -> bool {