mod_netconf: compatibility change to libnetconf 0.1.3

libnetconf's printing callback prototype changed to include verbose
level, we use these level now to distinguish apache's log level.
diff --git a/src/mod_netconf.c b/src/mod_netconf.c
index d3e7fbc..f70dce8 100644
--- a/src/mod_netconf.c
+++ b/src/mod_netconf.c
@@ -548,10 +548,22 @@
 }
 
 server_rec* clb_print_server;
-int clb_print(const char* msg)
+void clb_print(NC_VERB_LEVEL level, const char* msg)
 {
-	ap_log_error(APLOG_MARK, APLOG_INFO, 0, clb_print_server, msg);
-	return (0);
+	switch (level) {
+	case NC_VERB_ERROR:
+		ap_log_error(APLOG_MARK, APLOG_ERR, 0, clb_print_server, msg);
+		break;
+	case NC_VERB_WARNING:
+		ap_log_error(APLOG_MARK, APLOG_WARNING, 0, clb_print_server, msg);
+		break;
+	case NC_VERB_VERBOSE:
+		ap_log_error(APLOG_MARK, APLOG_INFO, 0, clb_print_server, msg);
+		break;
+	case NC_VERB_DEBUG:
+		ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, clb_print_server, msg);
+		break;
+	}
 }
 
 /*