xtrabackup doesn't build if several processors are used

slapos/profile/xtrabackup.cfg

@@ -34,3 +34,5 @@ environment =
   CPPFLAGS =-I${zlib:location}/include -I${ncurses:location}/include -I${readline:location}/include
   LDFLAGS =-L${zlib:location}/lib -Wl,-rpath -Wl,${zlib:location}/lib -L${ncurses:location}/lib -Wl,-rpath -Wl,${ncurses:location}/lib -L${readline:location}/lib -Wl,-rpath -Wl,${readline:location}/lib
   PATH=${autoconf:location}/bin:${automake-1.11:location}/bin:${libtool:location}/bin:${flex:location}/bin:%(PATH)s
+make-options =
+  -j1