title: Issue with LinqToDb T4 templates for a SqlLite database (using LoadSQLiteMetadata)
body: <p>I'm trying to use a local SqlLite database (in my app_data) folder with LinqToDb.</p>
  
  <p>Anybody an idea why LinqToDb cannot work with the following connectionstring ?</p>
  
  <pre><code>  &lt;connectionStrings&gt;
      &lt;add name="RecyclesDB"
           providerName="System.Data.SqlLite"
           connectionString="data source=|DataDirectory|Recycles.sqlite3;Version=3;" 
           /&gt;
    &lt;/connectionStrings&gt;
  </code></pre>
  
  <p>I can perfectly use this connectionstring to retrieve data the old-school way.</p>
  
  <pre><code>  SQLiteConnection sqlConn;
    var sqlCmd = new SQLiteCommand();
      using (sqlConn = new SQLiteConnection(ConfigurationManager.ConnectionStrings["RecyclesDB"].ConnectionString))
      {
        sqlConn.Open();
        sqlCmd.Connection = sqlConn;
   /* .... */               
      }
  </code></pre>
  
  <p>However, when I try to use LinqToDB with the following t4 template it fails</p>
  
  <pre><code>&lt;#@ template language="C#" debug="True" hostSpecific="True"                           #&gt;
  &lt;#@ output extension=".generated.cs"                                                  #&gt;
  &lt;#@ include file="$(ProjectDir)LinqToDB.Templates\LinqToDB.SQLite.Tools.ttinclude" #&gt;
  
  &lt;#@ include file="$(ProjectDir)LinqToDB.Templates\PluralizationService.ttinclude"     #&gt;
  
  &lt;#
      NamespaceName = "RecycleDashboard";
      LoadSQLiteMetadata(LoadSQLiteMetadata(@"C:\inetpub\RecycleDashboard\app_data", "Recycles.sqlite3"););
      GenerateModel();
  #&gt;
  </code></pre>
  
  <p>To specify the issue. The T4 template generates the models alright, but when I try to use these with the following code I get a null reference </p>
  
  <pre><code>    using (var db = new RecyclesDB())
      {
          var recycles =
              (from recycle in db.AppRecycles
               select recycle).ToList();
      }
  </code></pre>
  
  <p>The exception on new RecyclesDB() is : </p>
  
  <pre><code>System.NullReferenceException was unhandled by user code
    HResult=-2147467261
    Message=Object reference not set to an instance of an object.
    Source=linq2db
    StackTrace:
         at LinqToDB.Data.DataConnection..ctor(String configurationString) in i:\linq2db\Source\Data\DataConnection.cs:line 41
         at LinqToDB.Data.DataConnection..ctor() in i:\linq2db\Source\Data\DataConnection.cs:line 24
         at RecycleDashboard.RecyclesDB..ctor() in 
   ...
  </code></pre>
  
  <p>Anybody an idea what's wrong here ?</p>