TS-4250 fix (#563)
TS-4250 fix (#563)

* TS-4250 clang-format breaks on Centos 6

Change clang-format.sh to use native sha1sum command
when available.

* Fix shasum command error

We can safely remove the `-a 1` flag for the command since
the default for `shasum` is `-a 1` already.

vmamidi/trafficserver,pbchou/trafficserver,taoyunxing/trafficserver,chenglongwei/trafficserver,chenglongwei/trafficserver,taoyunxing/trafficserver,bryancall/trafficserver,chenglongwei/trafficserver,chenglongwei/trafficserver,rpufky/trafficserver,clearswift/trafficserver,rahmalik/trafficserver,vmamidi/trafficserver,pbchou/trafficserver,PSUdaemon/trafficserver,bryancall/trafficserver,rpufky/trafficserver,clearswift/trafficserver,pbchou/trafficserver,reveller/trafficserver,clearswift/trafficserver,duke8253/trafficserver,chitianhao/trafficserver,chitianhao/trafficserver,bryancall/trafficserver,pbchou/trafficserver,PSUdaemon/trafficserver,davidbz/trafficserver,dyrock/trafficserver,rpufky/trafficserver,persiaAziz/trafficserver,persiaAziz/trafficserver,dyrock/trafficserver,clearswift/trafficserver,bryancall/trafficserver,SolidWallOfCode/trafficserver,chenglongwei/trafficserver,reveller/trafficserver,persiaAziz/trafficserver,SolidWallOfCode/trafficserver,pbchou/trafficserver,davidbz/trafficserver,SolidWallOfCode/trafficserver,rahmalik/trafficserver,persiaAziz/trafficserver,rahmalik/trafficserver,PSUdaemon/trafficserver,rpufky/trafficserver,clearswift/trafficserver,chitianhao/trafficserver,davidbz/trafficserver,davidbz/trafficserver,rahmalik/trafficserver,rpufky/trafficserver,reveller/trafficserver,chitianhao/trafficserver,taoyunxing/trafficserver,taoyunxing/trafficserver,dyrock/trafficserver,chenglongwei/trafficserver,vmamidi/trafficserver,rahmalik/trafficserver,rahmalik/trafficserver,dyrock/trafficserver,clearswift/trafficserver,rahmalik/trafficserver,taoyunxing/trafficserver,rahmalik/trafficserver,duke8253/trafficserver,vmamidi/trafficserver,PSUdaemon/trafficserver,SolidWallOfCode/trafficserver,duke8253/trafficserver,rpufky/trafficserver,taoyunxing/trafficserver,PSUdaemon/trafficserver,rpufky/trafficserver,PSUdaemon/trafficserver,duke8253/trafficserver,pbchou/trafficserver,duke8253/trafficserver,vmamidi/trafficserver,PSUdaemon/trafficserver,persiaAziz/trafficserver,PSUdaemon/trafficserver,persiaAziz/trafficserver,reveller/trafficserver,reveller/trafficserver,chenglongwei/trafficserver,reveller/trafficserver,rpufky/trafficserver,rahmalik/trafficserver,SolidWallOfCode/trafficserver,PSUdaemon/trafficserver,taoyunxing/trafficserver,davidbz/trafficserver,duke8253/trafficserver,taoyunxing/trafficserver,vmamidi/trafficserver,chitianhao/trafficserver,chenglongwei/trafficserver,persiaAziz/trafficserver,bryancall/trafficserver,clearswift/trafficserver,persiaAziz/trafficserver,chitianhao/trafficserver,SolidWallOfCode/trafficserver,duke8253/trafficserver,davidbz/trafficserver,clearswift/trafficserver,bryancall/trafficserver,SolidWallOfCode/trafficserver,reveller/trafficserver,dyrock/trafficserver,reveller/trafficserver,chitianhao/trafficserver,reveller/trafficserver,rpufky/trafficserver,taoyunxing/trafficserver,clearswift/trafficserver,dyrock/trafficserver,dyrock/trafficserver