Updating the jacoco toolVersion (hyperledger#3041)

Jacoco failed to instrument some tests using the old version of the tool
when build under jdk17

Signed-off-by: Jiri Peinlich <jiri.peinlich@gmail.com>

Co-authored-by: Sally MacFarlane <sally.macfarlane@consensys.net>

build.gradle

@@ -95,7 +95,7 @@ allprojects {
   version = rootProject.version
 
   jacoco {
-    toolVersion = '0.8.6'
+    toolVersion = '0.8.7'
     if (project.tasks.findByName('referenceTests')) {
       applyTo referenceTests
     }