bugfixes in iso14443a.c and hf 14a reader

- introduced with the big frame and parity support (commit 6a1f2d82): tag responses with len%8 == 0 were dropped  - thanks iceman for testing and finding
- after unsuccessful hf 14a reader the field stayed on. Thanks to iceman for proposing the fix.

client/cmdhf14a.c

@@ -191,6 +191,11 @@ int CmdHF14AReader(const char *Cmd)
 	
 	if(select_status == 0) {
 		PrintAndLog("iso14443a card select failed");
+		// disconnect
+		c.arg[0] = 0;
+		c.arg[1] = 0;
+		c.arg[2] = 0;
+		SendCommand(&c);
 		return 0;
 	}