Reset max health attribute on server switch

[kennytv]

Attributes aren't reset, so the player sees the wrong amount of hearts when switching away from a server that changed the default value to a server without the change (since default attributes are not sent to the client). All of the other attributes either don't affect the client itself or are reset due to non-default values for players, so only the max health attribute is important.

[Xernium]

While we are on this subject, shouldn't JoinGame be resent if the next server is != the same mode (hardcore or not hardcore) ?

[Janmm14]

While we are on this subject, shouldn't JoinGame be resent if the next server is != the same mode (hardcore or not hardcore) ? @Xernium

This is already done if you enable the option "disableEntityMetadataRewrite" in Waterfall.

It should also be checked if that does reset the client's max health, in that caser this patch would need additional ifs so we don't send it if its not actually needed.