remove duplicate merge-node.cc in CMakeLists
remove duplicate merge-node.cc in CMakeLists

lirui-intel/Impala,lirui-intel/Impala,lnliuxing/Impala,theyaa/Impala,grundprinzip/Impala,gistic/PublicSpatialImpala,placrosse/ImpalaToGo,cchanning/Impala,rdblue/Impala,brightchen/Impala,henryr/Impala,rdblue/Impala,ibmsoe/ImpalaPPC,AtScaleInc/Impala,brightchen/Impala,placrosse/ImpalaToGo,ibmsoe/ImpalaPPC,XiaominZhang/Impala,cloudera/recordservice,bratatidas9/Impala-1,gistic/PublicSpatialImpala,kapilrastogi/Impala,lnliuxing/Impala,scalingdata/Impala,scalingdata/Impala,mapr/impala,rampage644/impala-cut,kapilrastogi/Impala,mapr/impala,placrosse/ImpalaToGo,AtScaleInc/Impala,bratatidas9/Impala-1,lirui-intel/Impala,gerashegalov/Impala,grundprinzip/Impala,cchanning/Impala,gerashegalov/Impala,mapr/impala,cgvarela/Impala,ibmsoe/ImpalaPPC,cgvarela/Impala,caseyching/Impala,brightchen/Impala,henryr/Impala,gerashegalov/Impala,bowlofstew/Impala,gistic/PublicSpatialImpala,grundprinzip/Impala,gerashegalov/Impala,AtScaleInc/Impala,caseyching/Impala,lnliuxing/Impala,XiaominZhang/Impala,ibmsoe/ImpalaPPC,henryr/Impala,rdblue/Impala,kapilrastogi/Impala,cloudera/recordservice,XiaominZhang/Impala,rampage644/impala-cut,ImpalaToGo/ImpalaToGo,gerashegalov/Impala,cloudera/recordservice,bowlofstew/Impala,caseyching/Impala,bratatidas9/Impala-1,cloudera/recordservice,rampage644/impala-cut,cchanning/Impala,cchanning/Impala,rampage644/impala-cut,bowlofstew/Impala,gistic/PublicSpatialImpala,henryr/Impala,scalingdata/Impala,kapilrastogi/Impala,cgvarela/Impala,bowlofstew/Impala,bowlofstew/Impala,brightchen/Impala,henryr/Impala,rdblue/Impala,lnliuxing/Impala,gistic/PublicSpatialImpala,AtScaleInc/Impala,brightchen/Impala,lirui-intel/Impala,rdblue/Impala,ibmsoe/ImpalaPPC,lnliuxing/Impala,andybab/Impala,caseyching/Impala,tempbottle/Impala,ImpalaToGo/ImpalaToGo,AtScaleInc/Impala,scalingdata/Impala,bratatidas9/Impala-1,placrosse/ImpalaToGo,bowlofstew/Impala,rdblue/Impala,placrosse/ImpalaToGo,kapilrastogi/Impala,tempbottle/Impala,theyaa/Impala,cloudera/recordservice,cchanning/Impala,ImpalaToGo/ImpalaToGo,brightchen/Impala,kapilrastogi/Impala,theyaa/Impala,cgvarela/Impala,grundprinzip/Impala,tempbottle/Impala,lnliuxing/Impala,AtScaleInc/Impala,theyaa/Impala,bratatidas9/Impala-1,caseyching/Impala,tempbottle/Impala,rdblue/Impala,theyaa/Impala,cgvarela/Impala,caseyching/Impala,mapr/impala,lirui-intel/Impala,XiaominZhang/Impala,gerashegalov/Impala,mapr/impala,cchanning/Impala,scalingdata/Impala,ImpalaToGo/ImpalaToGo,rampage644/impala-cut,XiaominZhang/Impala,tempbottle/Impala,bratatidas9/Impala-1,lnliuxing/Impala,bratatidas9/Impala-1,henryr/Impala,tempbottle/Impala,theyaa/Impala,caseyching/Impala,cgvarela/Impala,ibmsoe/ImpalaPPC,scalingdata/Impala,cloudera/recordservice,ImpalaToGo/ImpalaToGo,tempbottle/Impala,andybab/Impala,andybab/Impala,lirui-intel/Impala,andybab/Impala,placrosse/ImpalaToGo,grundprinzip/Impala,grundprinzip/Impala,theyaa/Impala,XiaominZhang/Impala,XiaominZhang/Impala,ibmsoe/ImpalaPPC,gistic/PublicSpatialImpala,andybab/Impala,cchanning/Impala,andybab/Impala,cgvarela/Impala,brightchen/Impala,gerashegalov/Impala,rampage644/impala-cut,kapilrastogi/Impala,cloudera/recordservice,lirui-intel/Impala,ImpalaToGo/ImpalaToGo,bowlofstew/Impala