fix select2 example
fix select2 example

shupan123/vue-fixed-type,th0r/vue,diermengdierme/vue,Endika/vue,karevn/vue,karevn/vue,lepture/vue,fergaldoyle/vue,fergaldoyle/vue,seedalpha/vue,diermengdierme/vue,karevn/vue,galenyuan/vue,lepture/vue,shupan123/vue-fixed-type,th0r/vue,Endika/vue,seedalpha/vue,diermengdierme/vue,Endika/vue,th0r/vue,fergaldoyle/vue,seedalpha/vue,galenyuan/vue,galenyuan/vue,shupan123/vue-fixed-type,lepture/vue