Remove ssl_cert_test sample app

Remove the ssl_cert_test sample application, as it uses
hardcoded certificates that moved, and is redundant with the x509
tests and applications. Fixes #1905.
diff --git a/programs/test/CMakeLists.txt b/programs/test/CMakeLists.txt
index 0ed7145..64b9637 100644
--- a/programs/test/CMakeLists.txt
+++ b/programs/test/CMakeLists.txt
@@ -16,12 +16,10 @@
 add_executable(benchmark benchmark.c)
 target_link_libraries(benchmark ${libs})
 
-add_executable(ssl_cert_test ssl_cert_test.c)
-target_link_libraries(ssl_cert_test ${libs})
 
 add_executable(udp_proxy udp_proxy.c)
 target_link_libraries(udp_proxy ${libs})
 
-install(TARGETS selftest benchmark ssl_cert_test udp_proxy
+install(TARGETS selftest benchmark udp_proxy
         DESTINATION "bin"
         PERMISSIONS OWNER_READ OWNER_WRITE OWNER_EXECUTE GROUP_READ GROUP_EXECUTE WORLD_READ WORLD_EXECUTE)