fix(database): upgrade error in pg database

Co-Authored-By: Aqr-K <95741669+Aqr-K@users.noreply.github.com>

database/versions/bf28a012734c_2_0_8.py

@@ -18,11 +18,11 @@ depends_on = None
 
 
 def upgrade() -> None:
-    # ### commands auto generated by Alembic - please adjust! ###
-    # 下载历史记录 增加下载器字段
-    with contextlib.suppress(Exception):
+    conn = op.get_bind()
+    inspector = sa.inspect(conn)
+    columns = inspector.get_columns('downloadhistory')
+    if not any(c['name'] == 'downloader' for c in columns):
         op.add_column('downloadhistory', sa.Column('downloader', sa.String(), nullable=True))
-    # ### end Alembic commands ###
 
 
 def downgrade() -> None: