Adding comment about setting some higher value for SQLITE_TIMEOUT, on

slower system - user may need to set the value to some higher value.

This value decide - for how long SQLITE operation will wait, before
throwing an operation timeout error because of the locked database.

Fixes #1329

web/config.py

@@ -167,7 +167,8 @@ SQLITE_PATH = os.path.join(
     'pgadmin4.db'
     )
 # SQLITE_TIMEOUT will define how long to wait before throwing the error -
-# OperationError due to database lock.
+# OperationError due to database lock. On slower system, you may need to change
+# this to some higher value.
 # (Default: 500 milliseconds)
 SQLITE_TIMEOUT = 500