Handle ClosedException in SqliteConnectionPool.

Author: rkistner

lib/src/connection_pool.dart

@@ -94,6 +94,8 @@ class SqliteConnectionPool with SqliteQueries implements SqliteConnection {
           }, lockTimeout: lockTimeout, debugContext: debugContext);
         } on TimeoutException {
           return false;
+        } on ClosedException {
+          return false;
         }
       });
 

test/basic_test.dart

@@ -383,6 +383,7 @@ void main() {
         // Second connection to sleep more than first connection
         'SELECT test_sleep(test_connection_number() * 10)'
       ]));
+      await db.initialize();
 
       final future1 = db.get('SELECT test_sleep(10) as sleep');
       final future2 = db.get('SELECT test_sleep(10) as sleep');