Revert "Gentoo's “fax compatibility” patch"

This reverts commit 3413f4c72a.

The patch was originally from Gernot Müller for patching a problem with incompatible fax receivers
[1].
It violates the CAPI specifications and therefore should not be included [2].

[1] http://osdir.com/ml/linux.isdn.capisuite.user/2004-05/msg00043.html
[2] https://github.com/larsimmisch/capisuite/pull/7#issuecomment-26650942

src/backend/connection.cpp

@@ -94,7 +94,7 @@ Connection::Connection (Capi* capi, _cdword controller, string call_from, bool c
 				CIPvalue=16;
 			break;
 			case FAXG3:
-				CIPvalue=4;
+				CIPvalue=17;
 			break;
 			default:
 				throw CapiExternalError("unsupported service given","Connection::Connection()");