Change rig_init logic to allow first char of '/' to mean a pathname and not a hostname

https://github.com/Hamlib/Hamlib/issues/492

src/misc.c

@@ -1636,6 +1636,7 @@ int HAMLIB_API parse_hoststr(char *hoststr, char host[256], char port[6])
 
     // Handle device names 1st
     if (strstr(hoststr, "/dev")) { return -1; }
+    if (strstr(hoststr, "/")) { return -1; } // posible path -- no hostname starts with /
 
     if (strncasecmp(hoststr, "com", 3) == 0) { return -1; }