Fix force_ssl environment handling

Fixes docker production example.

config/environments/production.rb

@@ -46,7 +46,7 @@ Rails.application.configure do
   # config.action_cable.allowed_request_origins = [ 'http://example.com', /http:\/\/example.*/ ]
 
   # Force all access to the app over SSL, use Strict-Transport-Security, and use secure cookies.
-  config.force_ssl = ENV.fetch('FORCE_SSL') { 'false' }
+  config.force_ssl = true if ENV.fetch('FORCE_SSL', false)
 
   # Include generic and useful information about system operation, but avoid logging too much
   # information to avoid inadvertent exposure of personally identifiable information (PII).

dotenv.example

@@ -109,7 +109,7 @@
 # OSEM_LOG_LEVEL=info
 
 # Force all access to the app over SSL, use Strict-Transport-Security, and use secure cookies.
-# FORCE_SSL=1
+# FORCE_SSL=true
 
 # Your skylight.io keys
 # SKYLIGHT_AUTHENTICATION=1234