Fix for CreateTable not always adding missing columns

This would happen when a previous INSERT/UPDATE/DELETE statement
query modified rows.  The existing code was incorrectly attempting
to check whether a CREATE IF NOT EXISTS statement did anything.
https://www.sqlite.org/c3ref/changes.html

Author: garthmz

src/SQLite.Net/SQLiteConnection.cs

@@ -335,12 +335,8 @@ public int CreateTable(Type ty, CreateFlags createFlags = CreateFlags.None)
             sbQuery.Append(")");
             var count = Execute(sbQuery.ToString());
 
-            if (count == 0)
-            {
-                //Possible bug: This always seems to return 0?
-                // Table already exists, migrate it
-                MigrateTable(map);
-            }
+            // add columns if necessary
+            MigrateTable(map);
 
             var indexes = new Dictionary<string, IndexInfo>();
             foreach (var c in mapColumns)