ci: Fix bug with coverage report generation

Many files were missing from the report because the build path was
excluded.

Change-Id: Ia7ecdf4a81b8d37cff6c3fd14c5de3407648d91c
diff --git a/.jenkins.d/30-coverage.sh b/.jenkins.d/30-coverage.sh
index a0e983e..b00354c 100755
--- a/.jenkins.d/30-coverage.sh
+++ b/.jenkins.d/30-coverage.sh
@@ -9,7 +9,7 @@
 if [[ $JOB_NAME == *"code-coverage" ]]; then
     gcovr --object-directory=build \
           --output=build/coverage.xml \
-          --exclude="$PWD/(build|tests|websocketpp)" \
+          --exclude="$PWD/(tests|websocketpp)" \
           --root=. \
           --xml
 fi