Before the commit some checks in the system test would try to verify
that different HTTP methods can be used and are functional. However,
until recently, it was not possible to tell from the output which
method was in fact used, so it turned out that +http-plain-get option
is broken.
This commit add the additional checks to prevent that from happening
in the future.
(cherry picked from commit 625991c810b4086a5fbfc48ecb54974f6b6e3f9a)
c8e551299c