Ensure that $ONOS_CELL variable will not be overwritten when bash profile is loaded
Ensure that $ONOS_CELL variable will not be overwritten when bash profile is loaded

you don't need to reload cell enviroment when open new terminal.

Change-Id: I073a6de71376e868d96e5216509c1d6b52bc7e52

osinstom/onos,Shashikanth-Huawei/bmp,VinodKumarS-Huawei/ietf96yang,maheshraju-Huawei/actn,sdnwiselab/onos,gkatsikas/onos,rvhub/onos,donNewtonAlpha/onos,LorenzReinhart/ONOSnew,chinghanyu/onos,donNewtonAlpha/onos,opennetworkinglab/onos,castroflavio/onos,lsinfo3/onos,planoAccess/clonedONOS,osinstom/onos,mengmoya/onos,sonu283304/onos,mengmoya/onos,oeeagle/onos,sdnwiselab/onos,kuujo/onos,sdnwiselab/onos,chinghanyu/onos,maheshraju-Huawei/actn,Shashikanth-Huawei/bmp,VinodKumarS-Huawei/ietf96yang,zsh2938/onos,sonu283304/onos,packet-tracker/onos,gkatsikas/onos,y-higuchi/onos,CNlukai/onos-gerrit-test,osinstom/onos,oplinkoms/onos,kuujo/onos,zsh2938/onos,oplinkoms/onos,planoAccess/clonedONOS,jinlongliu/onos,oplinkoms/onos,VinodKumarS-Huawei/ietf96yang,opennetworkinglab/onos,kuujo/onos,chenxiuyang/onos,lsinfo3/onos,osinstom/onos,planoAccess/clonedONOS,donNewtonAlpha/onos,packet-tracker/onos,castroflavio/onos,jmiserez/onos,kkkane/ONOS,kuujo/onos,jmiserez/onos,chenxiuyang/onos,chinghanyu/onos,sonu283304/onos,mengmoya/onos,y-higuchi/onos,oplinkoms/onos,LorenzReinhart/ONOSnew,Shashikanth-Huawei/bmp,kkkane/ONOS,sdnwiselab/onos,kuujo/onos,maheshraju-Huawei/actn,oeeagle/onos,oeeagle/onos,rvhub/onos,opennetworkinglab/onos,kuujo/onos,jmiserez/onos,zsh2938/onos,y-higuchi/onos,castroflavio/onos,gkatsikas/onos,mengmoya/onos,jinlongliu/onos,sdnwiselab/onos,opennetworkinglab/onos,packet-tracker/onos,LorenzReinhart/ONOSnew,oplinkoms/onos,rvhub/onos,rvhub/onos,gkatsikas/onos,oeeagle/onos,mengmoya/onos,Shashikanth-Huawei/bmp,planoAccess/clonedONOS,lsinfo3/onos,chenxiuyang/onos,CNlukai/onos-gerrit-test,Shashikanth-Huawei/bmp,oplinkoms/onos,CNlukai/onos-gerrit-test,maheshraju-Huawei/actn,y-higuchi/onos,sdnwiselab/onos,donNewtonAlpha/onos,zsh2938/onos,gkatsikas/onos,LorenzReinhart/ONOSnew,gkatsikas/onos,y-higuchi/onos,opennetworkinglab/onos,jmiserez/onos,VinodKumarS-Huawei/ietf96yang,kkkane/ONOS,VinodKumarS-Huawei/ietf96yang,jinlongliu/onos,oplinkoms/onos,lsinfo3/onos,packet-tracker/onos,CNlukai/onos-gerrit-test,chenxiuyang/onos,kuujo/onos,donNewtonAlpha/onos,castroflavio/onos,opennetworkinglab/onos,osinstom/onos,maheshraju-Huawei/actn,jinlongliu/onos,chinghanyu/onos,sonu283304/onos,kkkane/ONOS,LorenzReinhart/ONOSnew