tests: delete unused malformed.ndncert

malformed.ndncert was used in CommandValidator test suite
which has been deleted.

refs #2063

Change-Id: I7d123822c06fc2ccc4301c62ae7d312662659e38
diff --git a/tests/daemon/mgmt/malformed.ndncert b/tests/daemon/mgmt/malformed.ndncert
deleted file mode 100644
index 38b2fbb..0000000
--- a/tests/daemon/mgmt/malformed.ndncert
+++ /dev/null
@@ -1 +0,0 @@
-definitely not a key
\ No newline at end of file