Fix Sentry sending PII even when turned off

os.environ.get cannot get True/False flags from the environment
variables, so the result was being ignored. To fix this, use int values
and directly compare to see if users have enabled or disabled this
feature.

config/settings.py

@@ -273,7 +273,7 @@ def before_send(event, hint):
     integrations=[DjangoIntegration()],
     release=f"{SHIPPER_VERSION}",
     traces_sample_rate=sentry_transaction_rate,
-    send_default_pii=os.environ.get("SHIPPER_SENTRY_SDK_PII", default=False),
+    send_default_pii=(int(os.environ.get("SHIPPER_SENTRY_SDK_PII", default=0)) == 0),
     before_send=before_send,
     ignore_errors=[
         SSHException,

docs/sysadmin/Configuration.md

@@ -106,8 +106,10 @@ Copy the `.env.example` file and set the values:
     - Default: ``, disabled
   - `SHIPPER_SENTRY_SDK_PII`
     - Send potential personally-identifiable information (PII) to Sentry when submitting bug reports
-    - Default: `False`
-    - Warning: if set to `True`, shipper may send PII such as usernames and email addresses. Set to `False` in production.
+    - `0` -> disabled
+    - Any other value -> enabled
+    - Default: `0`
+    - Warning: if enabled, shipper may send PII such as usernames and email addresses. Set to `False` in production.
 
 ## `.env.db`