release: fix help text

The help text is read from the comments at the top of the script itself.
However, to detect what lines belongs to the help text, a range was
defined as:
- Start: any line starting with `# `
- End: any line starting `# Run with --no-test`

If any later line starts with `# ` is considered as a new matching
range, and from it to the end of the file is printed too.

Fix it by defining the range:
- Start: line 2
- End: blank line

(cherry picked from commit b1c8b5482c)

contrib/fedora/rpm/release.sh

@@ -75,7 +75,7 @@ print_usage() {
 die_help() {
     print_usage
     echo
-    sed -e '/^# /,/# Run with --no-test/!d' -e 's/^#\($\| \)/  /' "$BASH_SOURCE"
+    sed -e '2,/^$/!d' -e 's/^#\($\| \)/  /' "$BASH_SOURCE"
     exit 0
 }