build-unit-test-docker: Disable libpldm tests again

Now that we've merged the change of the option type from feature to
boolean[1], specify that the tests should not be built.

[1]: https://github.com/openbmc/libpldm/commit/65c64099e17ad81219726e790598cdc1f6e78f9a

Change-Id: Ife75a3505a6975174ffd8036ac042bdbcba27560
Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>
1 file changed