installer: remove guard when removing the bazel symlink
installer: remove guard when removing the bazel symlink

Previously we were not removing a potential existing symlink.
If this is a directory then the rm will fail, leading to
a failure of the installer, whereas we would create a
wrong symlink with the previous code.

Fixes #1219.

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MOS_MIGRATED_REVID=121262370

ButterflyNetwork/bazel,bazelbuild/bazel,hermione521/bazel,zhexuany/bazel,mrdomino/bazel,davidzchen/bazel,Asana/bazel,spxtr/bazel,twitter-forks/bazel,davidzchen/bazel,iamthearm/bazel,davidzchen/bazel,LuminateWireless/bazel,dropbox/bazel,meteorcloudy/bazel,mrdomino/bazel,juhalindfors/bazel-patches,kchodorow/bazel-1,dslomov/bazel-windows,LuminateWireless/bazel,variac/bazel,mbrukman/bazel,kchodorow/bazel-1,ulfjack/bazel,snnn/bazel,perezd/bazel,Asana/bazel,perezd/bazel,safarmer/bazel,damienmg/bazel,kchodorow/bazel,werkt/bazel,katre/bazel,ulfjack/bazel,snnn/bazel,snnn/bazel,ulfjack/bazel,bazelbuild/bazel,snnn/bazel,safarmer/bazel,ulfjack/bazel,davidzchen/bazel,dslomov/bazel-windows,akira-baruah/bazel,dslomov/bazel,kchodorow/bazel-1,dropbox/bazel,bazelbuild/bazel,LuminateWireless/bazel,ButterflyNetwork/bazel,mrdomino/bazel,mikelalcon/bazel,werkt/bazel,kchodorow/bazel-1,davidzchen/bazel,mikelikespie/bazel,damienmg/bazel,davidzchen/bazel,werkt/bazel,meteorcloudy/bazel,kchodorow/bazel,juhalindfors/bazel-patches,UrbanCompass/bazel,akira-baruah/bazel,bazelbuild/bazel,spxtr/bazel,meteorcloudy/bazel,variac/bazel,hermione521/bazel,LuminateWireless/bazel,dslomov/bazel,damienmg/bazel,dropbox/bazel,cushon/bazel,mikelalcon/bazel,dropbox/bazel,mikelikespie/bazel,bazelbuild/bazel,abergmeier-dsfishlabs/bazel,ButterflyNetwork/bazel,ButterflyNetwork/bazel,twitter-forks/bazel,spxtr/bazel,mbrukman/bazel,dslomov/bazel,bazelbuild/bazel,perezd/bazel,mikelikespie/bazel,zhexuany/bazel,Asana/bazel,mbrukman/bazel,zhexuany/bazel,hermione521/bazel,ButterflyNetwork/bazel,zhexuany/bazel,Asana/bazel,aehlig/bazel,katre/bazel,damienmg/bazel,juhalindfors/bazel-patches,dslomov/bazel-windows,dslomov/bazel-windows,UrbanCompass/bazel,cushon/bazel,abergmeier-dsfishlabs/bazel,perezd/bazel,kchodorow/bazel,werkt/bazel,kchodorow/bazel,ulfjack/bazel,mikelalcon/bazel,abergmeier-dsfishlabs/bazel,kchodorow/bazel,zhexuany/bazel,mbrukman/bazel,davidzchen/bazel,LuminateWireless/bazel,mrdomino/bazel,katre/bazel,dslomov/bazel,mbrukman/bazel,meteorcloudy/bazel,aehlig/bazel,juhalindfors/bazel-patches,twitter-forks/bazel,dslomov/bazel,meteorcloudy/bazel,juhalindfors/bazel-patches,iamthearm/bazel,mikelikespie/bazel,katre/bazel,spxtr/bazel,iamthearm/bazel,safarmer/bazel,UrbanCompass/bazel,aehlig/bazel,cushon/bazel,UrbanCompass/bazel,twitter-forks/bazel,kchodorow/bazel,mikelikespie/bazel,dslomov/bazel-windows,akira-baruah/bazel,iamthearm/bazel,mikelalcon/bazel,perezd/bazel,juhalindfors/bazel-patches,damienmg/bazel,aehlig/bazel,dropbox/bazel,kchodorow/bazel-1,mikelikespie/bazel,iamthearm/bazel,variac/bazel,zhexuany/bazel,iamthearm/bazel,katre/bazel,akira-baruah/bazel,variac/bazel,damienmg/bazel,akira-baruah/bazel,hermione521/bazel,ButterflyNetwork/bazel,dropbox/bazel,spxtr/bazel,snnn/bazel,safarmer/bazel,variac/bazel,hermione521/bazel,perezd/bazel,safarmer/bazel,abergmeier-dsfishlabs/bazel,werkt/bazel,Asana/bazel,katre/bazel,snnn/bazel,aehlig/bazel,hermione521/bazel,juhalindfors/bazel-patches,kchodorow/bazel-1,variac/bazel,Asana/bazel,aehlig/bazel,safarmer/bazel,dslomov/bazel,mrdomino/bazel,ulfjack/bazel,akira-baruah/bazel,twitter-forks/bazel,mbrukman/bazel,spxtr/bazel,UrbanCompass/bazel,twitter-forks/bazel,UrbanCompass/bazel,twitter-forks/bazel,werkt/bazel,perezd/bazel,abergmeier-dsfishlabs/bazel,mikelalcon/bazel,cushon/bazel,dslomov/bazel-windows,ulfjack/bazel,Asana/bazel,dslomov/bazel,mikelalcon/bazel,cushon/bazel,meteorcloudy/bazel,LuminateWireless/bazel,mrdomino/bazel,snnn/bazel,kchodorow/bazel,cushon/bazel,damienmg/bazel,aehlig/bazel,abergmeier-dsfishlabs/bazel,spxtr/bazel,meteorcloudy/bazel,variac/bazel