Document that search_path is reported by the server
Commit
28a1121fd912 marked search_path as GUC_REPORT, but failed to
update the relevant places in docs. There are two places listing the GUC
options reported to the client, so update both.
Reported-by: Tom Lane
Discussion: https://postgr.es/m/CAFh8B=k8s7WrcqhafmYhdN1+E5LVzZi_QaYDq8bKvrGJTAhY2Q@mail.gmail.com