Change plrust.allowed_dependencies to sighup context (#362)

Author: anth0nyleung

doc/src/dependencies.md

@@ -145,5 +145,6 @@ $$;
 ### Operational Notes
 
 - The dependency allow-list file path must be set in `plrust.allowed_dependencies` GUC value in `postgresql.conf`.
+- Changing the GUC value requires a configuration reload on the database to take effect.
 - The file must be readable by the user that runs Postgres backend connections. Typically, this user is named `postgres`.
 - Every time a `CREATE FUNCTION ... LANGUAGE plrust` statement is executed, the file is read, parsed, and validated. This arrangement allows administrators to edit it without needing to restart the Postgres cluster.

plrust/src/gucs.rs

@@ -66,7 +66,7 @@ pub(crate) fn init() {
         "The full path of a toml file containing crates and versions allowed when creating PL/Rust functions",
         "The full path of a toml file containing crates and versions allowed when creating PL/Rust functions",
         &PLRUST_ALLOWED_DEPENDENCIES,
-        GucContext::Postmaster,
+        GucContext::Sighup,
         GucFlags::default(),
     );