Fix JetConnection and DbConnectionStringBuilderExtensions issue.

src/System.Data.Jet/DbConnectionStringBuilderExtensions.cs

@@ -29,7 +29,7 @@ namespace System.Data.Jet
             }
             else if (IsOdbc(builder))
             {
-                builder["driver"] = Regex.Replace(value.Trim(), @"^(?<!\{).*(?!\})$", @"{$1}", RegexOptions.IgnoreCase);
+                builder["driver"] = Regex.Replace(value.Trim(), @"^(?<!\{)(.*)(?!\})$", @"{$1}", RegexOptions.IgnoreCase);
             }
             else
                 throw new InvalidOperationException("This extension method only supports OdbcConnectionStringBuilder and OleDbConnectionStringBuilder.");

src/System.Data.Jet/JetConnection.cs

@@ -80,7 +80,7 @@ namespace System.Data.Jet
         /// <exception cref="InvalidOperationException">This property can only be set as long as the connection is closed.</exception>
         public DbProviderFactory DataAccessProviderFactory
         {
-            get => JetFactory.InnerFactory;
+            get => JetFactory?.InnerFactory;
             set
             {
                 if (value == null)