ci: filter websocketpp files from lcov output

Change-Id: Ibd1ce39b0bf936e280e0277eaabf98cc68a5d656
diff --git a/.jenkins.d/30-coverage.sh b/.jenkins.d/30-coverage.sh
index 0a83447..0dbb03a 100755
--- a/.jenkins.d/30-coverage.sh
+++ b/.jenkins.d/30-coverage.sh
@@ -19,6 +19,11 @@
          --directory . \
          --no-external \
          --rc lcov_branch_coverage=1 \
+         --output-file build/coverage-with-tests-and-websocketpp.info
+
+    lcov --quiet \
+         --remove build/coverage-with-tests-and-websocketpp.info "$PWD/websocketpp/*" \
+         --rc lcov_branch_coverage=1 \
          --output-file build/coverage-with-tests.info
 
     lcov --quiet \