Fix uwsgi path location

After fixing the uwsgi installation from source and uwsgi path
location on devstack side, we need to apply the same fix in
devstack plugins side too.

- https://review.opendev.org/#/c/577779/

NOTE(priteau): Enable Zuul jobs that were disabled in commit
fe0fea186a now that they are passing.

Change-Id: I93a945f10cf2b8d8c16d43ee80f9a03d8acf4328
Related-Bug: #1883468

.zuul.yaml

@@ -36,7 +36,13 @@
       - publish-openstack-docs-pti
       - release-notes-jobs-python3
     check:
-      jobs: []
+      jobs:
+        - blazar-devstack-dsvm
+        - blazar-devstack-dsvm-ipv6-only
+        - openstack-tox-pylint:
+            voting: false
     gate:
       queue: blazar
-      jobs: []
+      jobs:
+        - blazar-devstack-dsvm
+        - blazar-devstack-dsvm-ipv6-only

devstack/plugin.sh

@@ -182,7 +182,7 @@ function blazar_setup_horizon {
 # start_blazar() - Start running processes, including screen
 function start_blazar {
     if [ "$BLAZAR_USE_MOD_WSGI" == "True" ]; then
-        run_process 'blazar-a' "$BLAZAR_BIN_DIR/uwsgi --ini $BLAZAR_UWSGI_CONF"
+        run_process 'blazar-a' "$(which uwsgi) --ini $BLAZAR_UWSGI_CONF"
     else
         run_process blazar-a "$BLAZAR_BIN_DIR/blazar-api --debug --config-file $BLAZAR_CONF_FILE"
     fi