add schema.patch to allow unused imports in schema file

planetwars-server/diesel.toml

@@ -4,3 +4,4 @@
 [print_schema]
 file = "src/schema.rs"
 import_types = ["diesel::sql_types::*", "crate::db_types::*"]
+patch_file = "src/schema.patch"

planetwars-server/src/schema.patch

@@ -0,0 +1,8 @@
+diff --git a/planetwars-server/src/schema.rs b/planetwars-server/src/schema.rs
+index 7f60d64..f88f687 100644
+--- a/planetwars-server/src/schema.rs
++++ b/planetwars-server/src/schema.rs
+@@ -0,0 +1,3 @@
++// This file is autogenerated by diesel
++#![allow(unused_imports)]
++

planetwars-server/src/schema.rs

@@ -1,3 +1,6 @@
+// This file is autogenerated by diesel
+#![allow(unused_imports)]
+
 table! {
     use diesel::sql_types::*;
     use crate::db_types::*;
@@ -73,11 +76,4 @@ joinable!(match_players -> bots (bot_id));
 joinable!(match_players -> matches (match_id));
 joinable!(sessions -> users (user_id));
 
-allow_tables_to_appear_in_same_query!(
-    bots,
-    code_bundles,
-    match_players,
-    matches,
-    sessions,
-    users,
-);
+allow_tables_to_appear_in_same_query!(bots, code_bundles, match_players, matches, sessions, users,);