lib/_data_ingestion: improve openLocalDB

lib/cli/commands/create_db.dart

@@ -25,11 +25,6 @@ class CreateDb extends Command {
       readWrite: true,
     );
 
-    if (db == null) {
-      print("Failed to open database");
-      exit(1);
-    }
-
     seedData(db).then((_) {
       print("Database created successfully");
     }).catchError((error) {

lib/cli/commands/query_kanji.dart

@@ -29,11 +29,6 @@ class QueryKanji extends Command {
       libsqlitePath: argResults!.option('libsqlite')!,
     );
 
-    if (db == null) {
-      print("Failed to open database");
-      exit(1);
-    }
-
     final result = await JaDBConnection(db).searchKanji('漢');
 
     if (result == null) {

lib/cli/commands/query_word.dart

@@ -29,11 +29,6 @@ class QueryWord extends Command {
       libsqlitePath: argResults!.option('libsqlite')!,
     );
 
-    if (db == null) {
-      print("Failed to open database");
-      exit(1);
-    }
-
     final result = await JaDBConnection(db).searchWord('kana');
 
     if (result == null) {