security: tolerate invalid or unsupported public keys in PIB

Change-Id: I3c1dd9d3fe81d0895e2d1706f0b29a8e61940beb
diff --git a/tests/unit/security/pib/certificate-container.t.cpp b/tests/unit/security/pib/certificate-container.t.cpp
index 0ba9956..55b013e 100644
--- a/tests/unit/security/pib/certificate-container.t.cpp
+++ b/tests/unit/security/pib/certificate-container.t.cpp
@@ -95,6 +95,13 @@
     BOOST_CHECK(container2.find(id1Key1Cert1.getName()) == container2.end());
     BOOST_CHECK(container2.find(id1Key1Cert2.getName()) != container2.end());
 
+    // removing the same certificate again is a no-op
+    container2.remove(id1Key1Cert1.getName());
+    BOOST_CHECK_EQUAL(container2.size(), 1);
+    BOOST_CHECK_EQUAL(container2.m_certs.size(), 1);
+    BOOST_CHECK(container2.find(id1Key1Cert1.getName()) == container2.end());
+    BOOST_CHECK(container2.find(id1Key1Cert2.getName()) != container2.end());
+
     // remove another certificate
     container2.remove(id1Key1Cert2.getName());
     BOOST_CHECK_EQUAL(container2.size(), 0);