Update function description for start_tls_proxy

In [1] the definition of the function was changed, adding the service
name as first parameter. Since this seems to have caused failures in
some plugins, at least update the function template accordingly.

[1] Ifcba410f5969521e8b3d30f02795541c1661f83a

Change-Id: I4d03957f8d3a18625f06379fb21aa7ba55e32797
1 file changed