二次函数<img class="kfformula" src="20190808/1565254258613538.png" data-latex="y={x}^{2}+mx+6"/>的顶点<img class="kfformula" src="20190808/1565254258861129.png" data-latex="\left ( {-1,5} \right )"/>,则<img class="kfformula" src="20190808/1565254258615064.png" data-latex="m"/>的值为( )