fix: parse "concurrent_adapters" in config correctly

Oops. Brown paper bag moment.

This undoes the type mangling to ensure the field value is never zero,
in favor of doing run time logic. That should be done with types some
day, but today I need to get running.

Signed-off-by: Lars Wirzenius <liw@liw.fi>

ci-broker.md

@@ -74,6 +74,23 @@ triggers:
       - !Branch "main"
 ~~~
 
+~~~{#broker-with-concurrent-adapters.yaml .file .yaml}
+db: ci-broker.db
+report_dir: reports
+queue_len_interval: 1min
+adapters:
+  mcadapterface:
+    command: ./adapter.sh
+    env:
+      RADICLE_NATIVE_CI: native-ci.yaml
+    sensitive_env:
+      API_KEY: xyzzy
+triggers:
+  - adapter: mcadapterface
+    filters:
+      - !Branch "main"
+~~~
+
 ~~~{#broker-with-two-triggers.yaml .file .yaml}
 db: ci-broker.db
 report_dir: reports
@@ -302,8 +319,8 @@ output is in the JSON format. It does not try to make sure the JSON
 matches the YAML semantically.
 
 ~~~scenario
-given a Radicle node, with CI configured with broker.yaml and adapter dummy.sh
-when I run cib --config broker.yaml config --output actual.json
+given a Radicle node, with CI configured with broker-with-concurrent-adapters.yaml and adapter dummy.sh
+when I run cib --config broker-with-concurrent-adapters.yaml config --output actual.json
 when I run jq . actual.json
 then command is successful
 ~~~