Hi,
OK, you’re using the Sonarqube Scanner release with the builtin JRE.
BTW, this is a gotcha 
Faced the same problem once after updating the scanner with
that version unintentional.
The builtin cacerts has this path, i.e. the windows client
sonar-scanner-4.0.0.1744-windows\jre\lib\security\cacerts
For an SSL connection to https://yoursonarhost the Java client = Sonarqube Scanner needs a
truststore = cacerts (default name) that has the RootCAs of your organization.
If your machine already has a Java runtime installed, it might be possible it has already the right cacerts file, then either
use the Sonarqube Scanner without JRE or
copy the cacerts to …\jre\lib\security\cacerts of your Sonarqube Scanner.
Otherwise ask your Java admin for the cacerts file.
If you’re on your own, this might be helpful:
https://drissamri.be/blog/2017/02/22/java-keystore-keytool-essentials/
Gilbert