configure: explain more libiconv check

diff --git a/configure b/configure
index 3a266ed7be7e3df10c13cced40d498d41d59549e..80e2b26942ddf4ade7c13500728c913700b5ddde 100755 (executable)
--- a/configure
+++ b/configure
@@ -252,6 +252,9 @@ int test(void)
 }
 '
 
+# a check for the external iconv library
+# for build-in libc iconv routines this check should fail
+# note that iconv routines are mandatory
 check_cc_snippet libiconv '
 #include <iconv.h>
 int test(void)