[victoria] Ensure get_requests_for_local_unit doesn't fail on incomplete relation

This is a rebuild/make sync for charms to pickup the fix in charmhelpers to fix
any inadvertant accesses of ['ca'] in the relation data before it is available
from vault in the certificates relation.  Fix in charmhelpers is in [1].

Also added bindep.txt for libpq-dev as the wheel for pysycopg-binary on
py36 no longer exists.

[1] https://github.com/juju/charm-helpers/pull/830
Closes-Bug: #2028683

Change-Id: I5836db2321ae20b2ff43002a7937ab364982aa95

bindep.txt

@@ -0,0 +1 @@
+libpq-dev [platform:dpkg]

rebuild

@@ -2,4 +2,4 @@
 # when dependencies of the charm change,
 # but nothing in the charm needs to.
 # simply change the uuid to something new
-53e34944-1178-11ec-9edc-c38acc23d967
+dae461b8-3d21-11ee-af7c-57ff7d3d9db9

src/build.lock

@@ -225,6 +225,12 @@
       "package": "pyaml",
       "vcs": null,
       "version": "21.10.1"
+    },
+    {
+      "type": "python_module",
+      "package": "Cython",
+      "vcs": null,
+      "version": "0.29.36"
     }
   ]
 }

tox.ini

@@ -92,7 +92,8 @@ commands = stestr run --slowest {posargs}
 [testenv:pep8]
 basepython = python3
 deps = flake8==3.9.2
-       charm-tools==2.8.3
+       PyYAML==6.0.1
+       charm-tools==2.8.6
 commands = flake8 {posargs} src unit_tests
 
 [testenv:func-target]