scanner-cli: sonar.http.timeout should be mapped to sonar.scanner.connectTimeout

[martin-strecker-sonarsource]

sonar-scanner-cli.jar version 6 supports http time-outs. We should map the value provided by sonar.http.timeout (which is only known by S4NET) to sonar.scanner.connectTimeout when we update the scanner-cli to version 6. The sonar-projects.properties file needs to be extended like so:
SonarScanner.MSBuild.exe begin /k:"Test" /d:sonar.host.url="http://localhost:9000" /d:sonar.token="<<~~>>" /d:sonar.http.timeout=5

Generated sonar-projects.properties in the end step:

sonar.host.url=http://localhost:9000
sonar.http.timeout=5
+sonar.scanner.connectTimeout=5

Related: #1983