Crash fix nullpointer

[michaelortmann]

Found by: Harekiet
Patch by: https://github.com/michaelortmann
Fixes:

One-line summary:

Additional description (if needed):
Bug since #1797, so it effects only current git branch, eggdrop 1.10.1 is fine.

Test cases demonstrating functionality (if applicable):
If a userfile contains bogus lines, like for example:
"--BOTFL"
instead of
"--BOTFL s"
the bot would crash.

Crash info showing type = 0x0:

#0  0x000055df7718d264 in find_user_entry (et=et@entry=0x55df771ad0e0 <USERENTRY_BOTFL>, u=u@entry=0x55df956a7210) at userent.c:1650
1650	    if (((*e)->type == et) || !strcasecmp((*e)->type->name, et->name)) {
(gdb) print **e
$1 = {next = 0x0, type = 0x0, u = {string = 0x55df9563f4d0 "", extra = 0x55df9563f4d0, list = 0x55df9563f4d0, ulong = 94418772423888}, name = 0x55df9563f4b0 "BOTFL\n"}