(PUP-11522) Ensure test is using the SSL_CERT_FILE

Previously, the test passed the CA cert to `create_context` and set
SSL_CERT_FILE, so it was possible for the test to pass when it shouldn't. Now
only do the latter to verify we can indeed connect when loading a CA from the
"system store" aka wherever openssl looks for trusted certs.

Also rename "system store" variable to "cert_file" to avoid confusion later when
the file is used to contain certs in an "external" store.

Author: joshcooper

spec/integration/http/client_spec.rb

@@ -77,8 +77,8 @@
       }
     }
 
-    let(:systemstore) do
-      res = tmpfile('systemstore')
+    let(:cert_file) do
+      res = tmpfile('cert_file')
       File.write(res, https_server.ca_cert)
       res
     end
@@ -96,9 +96,9 @@
     end
 
     it "connects when the server's CA is in the system store and the connection is mutually authenticated using create_context" do
-      Puppet::Util.withenv("SSL_CERT_FILE" => systemstore) do
+      Puppet::Util.withenv("SSL_CERT_FILE" => cert_file) do
         client_context = ssl_provider.create_context(
-          cacerts: [https_server.ca_cert], crls: [https_server.ca_crl],
+          cacerts: [], crls: [],
           client_cert: https_server.server_cert, private_key: https_server.server_key,
           revocation: false, include_system_store: true
         )
@@ -109,8 +109,8 @@
       end
     end
 
-    it "connects when the server's CA is in the system store and the connection is mutually authenticated uning load_context" do
-      Puppet::Util.withenv("SSL_CERT_FILE" => systemstore) do
+    it "connects when the server's CA is in the system store and the connection is mutually authenticated using load_context" do
+      Puppet::Util.withenv("SSL_CERT_FILE" => cert_file) do
         client_context = ssl_provider.load_context(revocation: false, include_system_store: true)
         https_server.start_server(ctx_proc: ctx_proc) do |port|
           res = client.get(URI("https://127.0.0.1:#{port}"), options: {ssl_context: client_context})
@@ -132,12 +132,12 @@
 
     it "connects when the server's CA is in the system store" do
       # create a temp cacert bundle
-      ssl_file = tmpfile('systemstore')
-      File.write(ssl_file, https_server.ca_cert)
+      cert_file = tmpfile('cert_file')
+      File.write(cert_file, https_server.ca_cert)
 
       # override path to system cacert bundle, this must be done before
       # the SSLContext is created and the call to X509::Store.set_default_paths
-      Puppet::Util.withenv("SSL_CERT_FILE" => ssl_file) do
+      Puppet::Util.withenv("SSL_CERT_FILE" => cert_file) do
         system_context = ssl_provider.create_system_context(cacerts: [])
         https_server.start_server do |port|
           res = client.get(URI("https://127.0.0.1:#{port}"), options: {ssl_context: system_context})