undo bump to CRDB_COUNT

Author: davepacheco

sled-agent/src/rack_setup/plan/service.rs

@@ -47,7 +47,7 @@ const BOUNDARY_NTP_COUNT: usize = 2;
 const NEXUS_COUNT: usize = 1;
 
 // The number of CRDB instances to create from RSS.
-const CRDB_COUNT: usize = 5;
+const CRDB_COUNT: usize = 1;
 
 // TODO(https://github.com/oxidecomputer/omicron/issues/732): Remove
 // when Nexus provisions Oximeter.