Fix read_lang() crash on malformed language file

[michaelortmann]

Found by: michaelortmann
Patch by: michaelortmann
Fixes:

One-line summary:
Fix read_lang() crash on malformed language file

Additional description (if needed):
eggdrop crashes on malformed (missing ,) language file
Example:
Edit language/core.english.lang
Change (remove ,)
0x132,inactive
Into
0x132inactive

$ ./eggdrop -t BotA.conf 
* Please report problem to https://github.com/eggheads/eggdrop/issues
* Check doc/BUG-REPORT on how to do so.
Segmentation fault (core dumped)

While fixing the parser to not crash, memory allocation also got optimized.
Before:

$ ltrace ./eggdrop -t BotA.conf 2>&1|grep realloc|wc -l
.die
686

After:

$ ltrace ./eggdrop -t BotA.conf 2>&1|grep realloc|wc -l
.die
75

Test cases demonstrating functionality (if applicable):
The new code has been battletested with lowering initial read_lang() char lbuf[256]; size of 256 to make it grow the ltext buffer with realloc().