Remove ineffective statements.

The removed code was introduced in revision ba58651e5a ("Fix for
CreateFolder with SSH"), presumably to fix an issue where some SSH
backends did not like the trailing slash when creating new folders.
However, since we are not using the output argument of the call to
Substring, these statements have no effect.

Duplicati/Library/Backend/SSHv2/SSHv2Backend.cs

@@ -112,11 +112,7 @@ namespace Duplicati.Library.Backend
         public void CreateFolder()
         {
             CreateConnection();
-            //Bugfix, some SSH servers do not like a trailing slash
-            string p = m_path;
-            if (p.EndsWith("/", StringComparison.Ordinal))
-                p.Substring(0, p.Length - 1);
-            m_con.CreateDirectory(p);
+            m_con.CreateDirectory(m_path);
         }
 
         public string DisplayName