chore: fix comment typo (#6573)
chore: fix comment typo (#6573)

correct "a input" to "an input"
cnchanning/vue,vuejs/vue,Hanks10100/vue,lizhiyao/vue,cnchanning/vue,Kingwl/vue,Jinjiang/vue,Kingwl/vue,cnchanning/vue,KingMario/vue,Ddder-FE/vue,Ddder-FE/vue,vuejs/vue,Kingwl/vue,Jinjiang/vue,optimizely/vue,lizhiyao/vue,Hanks10100/vue,lizhiyao/vue,Ddder-FE/vue,Hanks10100/vue,vuejs/vue,Jinjiang/vue,Ddder-FE/vue,vuejs/vue,Jinjiang/vue,KingMario/vue,KingMario/vue,Hanks10100/vue,KingMario/vue,Kingwl/vue,lizhiyao/vue