do not fail if coverage report could not be produced. This happens frequently...

do not fail if coverage report could not be produced. This happens frequently due to bugs (?) in lcov on Ubuntu 1604

vars/helper.groovy

@@ -206,10 +206,10 @@ def doCoverage(String label, String buildType) {
   sh """
     cd /scratch/build-${parentJob}
     sudo -u msk_jenkins make coverage || true
-    sudo -u msk_jenkins /common/lcov_cobertura-1.6/lcov_cobertura/lcov_cobertura.py coverage.info
+    sudo -u msk_jenkins /common/lcov_cobertura-1.6/lcov_cobertura/lcov_cobertura.py coverage.info || true
     
-    sudo -u msk_jenkins cp -r coverage_html ${WORKSPACE}
-    sudo -u msk_jenkins cp -r coverage.xml ${WORKSPACE}
+    sudo -u msk_jenkins cp -r coverage_html ${WORKSPACE} || true
+    sudo -u msk_jenkins cp -r coverage.xml ${WORKSPACE} || true
   """
   
   // stash cobertura coverage report result for later publication
@@ -217,7 +217,7 @@ def doCoverage(String label, String buildType) {
   
   // publish HTML coverage report now, since it already allows publication of multiple distinguised reports
   publishHTML (target: [
-      allowMissing: false,
+      allowMissing: true,
       alwaysLinkToLastBuild: false,
       keepAll: false,
       reportDir: "coverage_html",