[FAB-13292] fix version check in bootstrap.sh
[FAB-13292] fix version check in bootstrap.sh

The check for the specified version string should be augmented by wrapping
the command line argument in quotation marks: if no version is provided
(which is allowed), the test fails because the non-quoted variable disappears
and the test bash built-in has two illegal switches next to one another,
leading to

bash: line 181: [: too many arguments

Change-Id: I6ca1d654ef38d6ea0fabcd3ca24c0d861321d489
Signed-off-by: Alessandro Sorniotti <f32b00f17cd31d4086a37e20e6815a9429f62787@sopit.net>

manish-sethi/fabric-sidedb,stemlending/fabric,muralisrini/fabric,manish-sethi/fabric-sidedb,manish-sethi/fabric-sidedb,manish-sethi/fabric,hyperledger/fabric,manish-sethi/fabric,manish-sethi/fabric-sidedb,manish-sethi/fabric-sidedb,muralisrini/fabric,stemlending/fabric,muralisrini/fabric,jimthematrix/fabric,jimthematrix/fabric,hyperledger/fabric,manish-sethi/fabric-sidedb,stemlending/fabric,stemlending/fabric,manish-sethi/fabric-sidedb,binhn/fabric,binhn/fabric,binhn/fabric