ecore: Don't check ecore-con dependencies if there are none.

"pkg-config --exists <none>" will return false, thus failing the
configure phase. Not sure if building ecore-con without curl makes sense
though.

SVN revision: 80265

configure.ac

@@ -2368,7 +2368,9 @@ fi
 
 AM_CONDITIONAL([HAVE_CARES], [test "x${have_cares}" = "xyes"])
 
-PKG_CHECK_MODULES([ECORE_CON], [${requirements_pc_deps_ecore_con}])
+if test "x${requirements_pc_deps_ecore_con}" != "x" ; then
+   PKG_CHECK_MODULES([ECORE_CON], [${requirements_pc_deps_ecore_con}])
+fi
 
 case "$host_os" in
    mingw32ce*)