argus 3.0.5.4 build errata

[John Gerth]

There's a typo in in the configure script (see below) which causes the Makefile
to set COMPATLIB = -lm instead of '-lm -lz' which causes the ld for argus to
fail because it can't find compress().

The fix is to change 'elseif' to 'else'

-- 
John Gerth      gerth at graphics.stanford.edu  Gates 378   (650) 725-3273  fax 723-0033

********* configure
checking for tzset... yes
./configure: line 13971: elseif: command not found
checking for .threads... yes


********* make

gcc -O3 -I.  -I./../include  -DHAVE_CONFIG_H -o ../bin/argus argus.o ArgusModeler.o ArgusSource.o ArgusUtil.o ArgusOutput.o ArgusUdp.o ArgusTcp.o
ArgusIcmp.o ArgusIgmp.o ArgusEsp.o ArgusArp.o ArgusFrag.o ArgusUdt.o ArgusLcp.o ArgusIsis.o ArgusAuth.o Argus802.11.o ArgusApp.o ArgusEvents.o
ArgusNetflow.o  -lpcap -lpthread  -lwrap -lnsl  -lm ../lib/argus_common.a -lm
ArgusEvents.o: In function `ArgusGenerateEventRecord':
ArgusEvents.c:(.text+0x1a0): undefined reference to `compress'
ArgusEvents.c:(.text+0x52a): undefined reference to `compress'
collect2: ld returned 1 exit status
make[1]: *** [../bin/argus] Error 1