fix(test): use valid Math.random() return value in DVB A168 test

Replace stub.returns(1) with stub.returns(0.99) since Math.random()
returns [0, 1) exclusive. The value 1.0 masked the off-by-one bug
because it produced the same result with both formulas.

Author: PascalThuet

test/unit/test/streaming/streaming.utils.DVBSelector.js

@@ -141,8 +141,8 @@ describe('BaseURLResolution/DVBSelector', function () {
         expect(secondSelection.dvbPriority).to.equal(3);
         expect(secondSelection.serviceLocation).to.equal('C');
 
-        // Math.random (called in select()) will return 1
-        stub.returns(1);
+        // Math.random (called in select()) will return 0.99 (valid range: [0, 1))
+        stub.returns(0.99);
 
         blacklist.push(secondSelection.serviceLocation);