Change sleep times to follow core functions (for `sendwhatmsg_instantly` function)

[dzonimn]

Hi, I was recently trying to use this library but found that the instant version of the sendwhatmsg function didn't seem to work.

It would type in the message in the text box, but it didn't seem to click into the text box before pressing enter. The original functions worked, so after some digging into how the original functions did it, I noticed that there were a difference in sleep times. Adjusting the instant function with the non-instant function led to the instant function working as expected.

On a different note, in my gut feeling, I feel like this part of the code seems like code that should exist in the core file, but I can't say I'm too familiar with the codebase to go refactoring things in a big way right now.

Do let me know if I should provide more information. Keep up the good work! :)