Patch by Gerardo Marset <gammer1994@gmail.com>

--- ettercap-0.7.3.orig/configure
+++ ettercap-0.7.3/configure
@@ -8346,7 +8346,7 @@
   exit 1
 fi
 gentoo_lt_version="1.5.18"
-gentoo_ltmain_version=`grep '^[:space:]*VERSION=' $ltmain | sed -e 's|^[:space:]*VERSION=||'`
+gentoo_ltmain_version=`grep '^[[:space:]]*VERSION=' $ltmain | sed -e 's|^[:space:]*VERSION=||'`
 if test "$gentoo_lt_version" != "$gentoo_ltmain_version"; then
   echo "$as_me:$LINENO: result: no" >&5
 echo "${ECHO_T}no" >&6