[HTTP] Add java.lang.NullPointerException to catch while parsing json

Probably after updating jenkins/groovy that JsonSlurperClassic() also
fixed/changed something and now when it tries to parse output like
'127.0.0.1' or event just a single number it throws
java.lang.NullPointerException exception and it breaks flow of
sendHttpRequest() function.

Related-To: PRODX-10294
Change-Id: Ia9ec379256771f1384fd3f57c5e31d9ce27bae56
1 file changed