Merge branch 'nuke-ugly-spaces-in-changelog-generator' into 'master'

Remove trailing whitespace when generating changelog entry

## What does this MR do?

It removes the trailing whitespace when a new changelog entry file is created by our changelog generator.

## Why was this MR needed?

If you run `bin/changelog` without passing merge request and author, these two lines are empty, with a trailing space at the end. I have to remove this trailing space manually.

See merge request !7948

bin/changelog

@@ -84,12 +84,15 @@ class ChangelogEntry
     end
   end
 
+  private
+
   def contents
-    YAML.dump(
+    yaml_content = YAML.dump(
       'title'         => title,
       'merge_request' => options.merge_request,
       'author'        => options.author
     )
+    remove_trailing_whitespace(yaml_content)
   end
 
   def write
@@ -101,8 +104,6 @@ class ChangelogEntry
     exec("git commit --amend")
   end
 
-  private
-
   def fail_with(message)
     $stderr.puts "\e[31merror\e[0m #{message}"
     exit 1
@@ -160,6 +161,10 @@ class ChangelogEntry
   def branch_name
     @branch_name ||= %x{git symbolic-ref --short HEAD}.strip
   end
+
+  def remove_trailing_whitespace(yaml_content)
+    yaml_content.gsub(/ +$/, '')
+  end
 end
 
 if $0 == __FILE__

changelogs/unreleased/nuke-ugly-spaces-in-changelog-generator.yml

+---
+title: Remove trailing whitespace when generating changelog entry
+merge_request: 7948
+author: