security: Pair-up Tpm and Pib in KeyChain

In this commit, we also change the HOME setting for test cases.

Change-Id: I7fa15461555b3519d9d2005c6956c167ed07d66f
Refs: #2242
Refs: #2260
diff --git a/tests/unit-tests/transport/test-homes/unix-transport/ok-omitted-unix-socket-omitted-protocol/.ndn/client.conf b/tests/unit-tests/transport/test-homes/unix-transport/ok-omitted-unix-socket-omitted-protocol/.ndn/client.conf
index e69de29..2c4c027 100644
--- a/tests/unit-tests/transport/test-homes/unix-transport/ok-omitted-unix-socket-omitted-protocol/.ndn/client.conf
+++ b/tests/unit-tests/transport/test-homes/unix-transport/ok-omitted-unix-socket-omitted-protocol/.ndn/client.conf
@@ -0,0 +1,3 @@
+; Empty client.conf is unfeasible in automated tests,
+; see tests/unit-tests/security/config-file-readme.txt.
+pib=pib-sqlite3:/tmp/test/ndn-cxx/keychain/sqlite3-empty/
\ No newline at end of file