Removed extra parenthesis

There was an extra left parenthesis with no matching right one, so I removed it.

entity-framework/core/dbcontext-configuration/index.md

@@ -241,7 +241,7 @@ The following table contains examples for common database providers.
 | SQLite                       | `.UseSqlite(connectionString)`                | [Microsoft.EntityFrameworkCore.Sqlite](https://www.nuget.org/packages/Microsoft.EntityFrameworkCore.Sqlite/)
 | EF Core in-memory database   | `.UseInMemoryDatabase(databaseName)`          | [Microsoft.EntityFrameworkCore.InMemory](https://www.nuget.org/packages/Microsoft.EntityFrameworkCore.InMemory/)
 | PostgreSQL*                  | `.UseNpgsql(connectionString)`                | [Npgsql.EntityFrameworkCore.PostgreSQL](https://www.nuget.org/packages/Npgsql.EntityFrameworkCore.PostgreSQL/)
-| MySQL/MariaDB*               | `.UseMySql((connectionString)`                | [Pomelo.EntityFrameworkCore.MySql](https://www.nuget.org/packages/Pomelo.EntityFrameworkCore.MySql/)
+| MySQL/MariaDB*               | `.UseMySql(connectionString)`                | [Pomelo.EntityFrameworkCore.MySql](https://www.nuget.org/packages/Pomelo.EntityFrameworkCore.MySql/)
 | Oracle*                      | `.UseOracle(connectionString)`                | [Oracle.EntityFrameworkCore](https://www.nuget.org/packages/Oracle.EntityFrameworkCore/)
 
 *These database providers are not shipped by Microsoft. See [Database Providers](xref:core/providers/index) for more information about database providers.