Fix truncation / buffer sizes

[michaelortmann]

Found by: michaelortmann
Patch by: michaelortmann
Fixes:

One-line summary:
Fix truncation / buffer sizes

Additional description (if needed):
Found with #1028, but can/should be merged independently before #1028.

Test cases demonstrating functionality (if applicable):
it should be possible to demonstrate a truncated notice in

eggdrop/src/mod/irc.mod/msgcmds.c

Line 491 in d5eff2a

egg_snprintf(s1, sizeof s1, "NOTICE %s :[%s] %s: %s.", nick, u2->handle,

and to demonstrate that this PR will fix this. But it should be enough to know, that this PR will fix compiler warnings that would occur after #1028.

[vanosg]

good catches! can you double-check these values and adjust if necessary?

[michaelortmann]

Geo: For the uhostlen mess see also #650. Many compiler warnings are currently shaddowed by using egg_snprintf() instead snprintf(). For that see also #1028. There is more to come, but i want to see this PR merged rather soon instead of making one big PR, because not all compiler warnings about buffer sizes / truncation are equal. This here is one of the more serious ones and not only cosmetic.