Remove unnecessary change

xmtp_mls/src/groups/mod.rs

@@ -129,7 +129,7 @@ where
 
         mls_group.save(provider.key_store())?;
         let group_id = mls_group.group_id().to_vec();
-        let stored_group = StoredGroup::new(group_id.clone(), now_ns() as i64, membership_state);
+        let stored_group = StoredGroup::new(group_id.clone(), now_ns(), membership_state);
         stored_group.store(&mut conn)?;
 
         Ok(Self::new(client, group_id, stored_group.created_at_ns))

xmtp_mls/src/storage/encrypted_store/group.rs

@@ -141,7 +141,7 @@ pub(crate) mod tests {
     pub fn generate_group(state: Option<GroupMembershipState>) -> StoredGroup {
         StoredGroup {
             id: rand_vec(),
-            created_at_ns: now_ns() as i64,
+            created_at_ns: now_ns(),
             membership_state: state.unwrap_or(GroupMembershipState::Allowed),
         }
     }

xmtp_mls/src/utils/time.rs

@@ -1,9 +1,9 @@
 use std::time::{SystemTime, UNIX_EPOCH};
 
-pub fn now_ns() -> u64 {
+pub fn now_ns() -> i64 {
     let now = SystemTime::now();
 
     now.duration_since(UNIX_EPOCH)
         .expect("Time went backwards")
-        .as_nanos() as u64
+        .as_nanos() as i64
 }