Andrew Savchenko

Support legacy aclocal: add empty m4 dir

Looks like old aclocal versions die if with -I m4 m4 dir doesn't
exist, 1.14 works fine without this chanege.
... ... @@ -59,7 +59,6 @@ tmp
/install-sh
/libtool
/ltmain.sh
/m4
/missing
/pkgconfig/clsync.pc
/stamp-h1
... ...
*
!.gitignore
... ...