rpm: add required packages

Motivation:
dCache startup scripts depend on commands `which`, `hostname` and `ps`.
Despite the fact, that those commands typically exist on regular
installations, some minimal setups don't provide them. Thus, dCache
fails to operate.

Modification:
Explicitly add required packages into rpm spec.

Result:
correct installation on minimal OS environments.

Acked-by: Lea Morschel
Acked-by: Albert Rossi
Target: master
Require-book: no
Require-notes: yes

packages/fhs/src/main/rpm/dcache-server.spec

@@ -11,6 +11,8 @@ AutoReqProv: no
 
 Requires(pre): shadow-utils
 Requires: which
+Requires: hostname
+Requires: procps-ng
 Requires: java-11-headless
 
 %{?systemd_requires}