allow no allowed_origin_requests_per_period

TODO.md

@@ -245,6 +245,8 @@ These are roughly in order of completition
 
 These are not yet ordered. There might be duplicates. We might not actually need all of these.
 
+- [ ] remove the "metered" crate now that we save aggregate queries?
+- [ ] remove/change the "active_requests" counter? maybe only once we have dynamic soft limits?
 - [ ] refactor so configs can change while running
   - this will probably be a rather large change, but is necessary when we have autoscaling
   - create the app without applying any config to it

web3_proxy/src/config.rs

@@ -54,6 +54,7 @@ pub struct TopConfig {
 pub struct AppConfig {
     /// Request limit for allowed origins for anonymous users.
     /// These requests get rate limited by IP.
+    #[serde(default = "default_allowed_origin_requests_per_period")]
     pub allowed_origin_requests_per_period: HashMap<String, u64>,
 
     /// EVM chain id. 1 for ETH
@@ -133,6 +134,10 @@ pub struct AppConfig {
     pub volatile_redis_max_connections: Option<usize>,
 }
 
+fn default_allowed_origin_requests_per_period() -> HashMap<String, u64> {
+    HashMap::new()
+}
+
 /// This might cause a thundering herd!
 fn default_min_sum_soft_limit() -> u32 {
     1