Fix crash on VPB exception when no hardware is present.

(closes issue #14970)
Reported by: tzafrir
Patches:
      vpb_exception.diff uploaded by tzafrir (license 46)
Tested by: markwaters


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@228079 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_vpb.cc

@@ -2718,7 +2718,7 @@ static enum ast_module_load_result load_module()
 	int num_cards = 0;
 	try {
 		num_cards = vpb_get_num_cards();
-	} catch (VpbException e) {
+	} catch (std::exception e) {
 		ast_log(LOG_ERROR, "No Voicetronix cards detected\n");
 		return AST_MODULE_LOAD_DECLINE;
 	}