fix w2form.getChanges()
fix w2form.getChanges()

fix w2form.getChanges(), see issue #1948

aadrian/w2ui,vitmalina/w2ui,vitmalina/w2ui,mpf82/w2ui,mpf82/w2ui,vitmalina/w2ui,aadrian/w2ui,vitmalina/w2ui,mpf82/w2ui,mpf82/w2ui,aadrian/w2ui,aadrian/w2ui,mpf82/w2ui,aadrian/w2ui,aadrian/w2ui,mpf82/w2ui,mpf82/w2ui,aadrian/w2ui,vitmalina/w2ui,vitmalina/w2ui,vitmalina/w2ui