Description:
------------
./configure reports missing iconv when in fact ttf is missing

Configuration line was:

./configure --with-mysql --with-gd --with-ttf --enable-track-vars  --with-apxs2=/usr/local/apache2/bin/apxs --with-jpeg  --with-png --with-zlib --with-tiff --with-gdbm --with-pdflib=/usr/local --with-freetype  --enable-mbstring

failed to compile complaining about iconv install but iconv is correctly installed.

Reproduce code:
---------------
Run above configuration line with no libttf

Expected result:
----------------
Successful compile

Actual result:
--------------
checking for iconv support... yes
checking for iconv... no
checking for libiconv... no
checking for libiconv in -liconv... no
checking for iconv in -liconv... no
configure: error: Please reinstall the iconv library.


Config.log shows the issue:

int main() {
libiconv()
; return 0; }
configure:44525: checking for iconv in -liconv
configure:44544: gcc -o conftest -g -O2  -Wl,-rpath,/usr/local/lib -L/usr/local/lib  conftest.c -liconv  -lttf -lpng -lz -lgdbm -lz -lresolv -lm -ldl -lnsl  -lxml2 -lz -lm -lxml2 -lz -lm 1>&5
/usr/lib/gcc/i486-slackware-linux/3.4.6/../../../../i486-slackware-linux/bin/ld: cannot find -lttf
collect2: ld returned 1 exit status
configure: failed program was:
#line 44533 "configure"
#include "confdefs.h"
/* Override any gcc2 internal prototype to avoid an error.  */
/* We use char because int might match the return type of a gcc2
    builtin and then its argument prototype would still apply.  */
char iconv();

int main() {
iconv()
; return 0; }