Use sudo iniset to modify /etc files

The existing mysql code is wrong and not detected as failing [1], and
boto config requires work-arounds [2,3] that are all fairly ugly.  Use
-sudo argument to iniset to handle this.

[1] I24388b5de777995f92d73076524122cf599d6371
[2] I5f4c43bbbe477c570936e2e40ac05cc38febbb3f
[3] Ib7556dac9aaaf2f3c96237e0ca28ed6ae1b1b7ac

Change-Id: Iaceb8d42ce37be728adae6fd0a30a1f9d33d4029
diff --git a/lib/tempest b/lib/tempest
index be24da6..645d245 100644
--- a/lib/tempest
+++ b/lib/tempest
@@ -546,7 +546,7 @@
 
     if is_ssl_enabled_service "key" || is_service_enabled tls-proxy; then
         # Use the ``BOTO_CONFIG`` environment variable to point to this file
-        iniset $BOTO_CONF Boto ca_certificates_file $SSL_BUNDLE_FILE
+        iniset -sudo $BOTO_CONF Boto ca_certificates_file $SSL_BUNDLE_FILE
         sudo chown $STACK_USER $BOTO_CONF
     fi