fix(meteor): pin session@1.2.2, 1.2.3 needs a newer Meteor core

session@1.2.3 requires meteor@2.3.1 (Meteor 3.3+) and this app is on 3.1, so
every `meteor test` and `meteor build` since 685af89 died at version selection
with "Constraint meteor@2.3.1 is not satisfied by meteor 2.0.2". 1.2.2 is the
release that ships with Meteor 3.1 and gives Bert.alert() the same Session var.

Nothing caught it because CI only builds the image and never ran the suite —
which is what the rest of this phase is about.

.meteor/packages

@@ -9,7 +9,7 @@ mobile-experience@1.1.2       # Packages for a great mobile UX
 mongo@2.0.3                   # The database Meteor supports right now
 reactive-var@1.0.13            # Reactive variable for tracker
 tracker@1.3.4                 # Meteor's client-side reactive programming library
-session@1.2.3                  # Reactive Session var, required by themeteorchef:bert's Bert.alert()
+session@1.2.2                  # Reactive Session var, required by themeteorchef:bert's Bert.alert()
 
 standard-minifier-css@1.9.3   # CSS minifier run for production mode
 standard-minifier-js@3.0.0    # JS minifier run for production mode

.meteor/versions

@@ -92,13 +92,14 @@ random@1.2.2
 rate-limit@1.1.2
 react-fast-refresh@0.2.9
 react-meteor-data@3.0.6
+reactive-dict@1.3.2
 reactive-var@1.0.13
 reload@1.3.2
 retry@1.1.1
 reywood:publish-composite@1.6.0
 routepolicy@1.1.2
 service-configuration@1.3.5
-session@1.2.3
+session@1.2.2
 sha@1.0.10
 shell-server@0.6.1
 simple:json-routes@3.0.0