newline added to block when 'keepUnassigned' and 'keepBlockTags' are true

[schmuli]

When using GHR with options keepUnassigned and keepBlockTags, every time I run the plugin, a newline is added below the content, but above the 'endbuild' comment.

For example:

    <!-- build:icon -->
    <link rel="shortcut icon"
        href="../assets/favicon64.png" />
    <!-- endbuild -->

    <link href='https://fonts.googleapis.com/css?family=Inconsolata|Open+Sans:300,400'
        rel='stylesheet'
        type='text/css'>

After a few runs, I get this:

    <!-- build:icon -->
    <link rel="shortcut icon"
        href="../assets/favicon64.png" />




    <!-- endbuild -->

    <link href='https://fonts.googleapis.com/css?family=Inconsolata|Open+Sans:300,400'
        rel='stylesheet'
        type='text/css'>

This is very similar to #42 but here the newline is getting added before the closing comment, rather than below.

By the way, I tried debugging this issue, and what I noticed is that because during this particular run of the plugin, the icon block didn't have any matching task in the config and therefore no replacements, the Block class is returning originalContent, and since it already has a newline, joining that with the beginTag and the endTag is what is adding extra linefeeds. I was able to fix this locally by changing:

    if (!this.replacements.length) {
        return this.config.keepUnassigned ? [this.originalContent] : [];
    }

to:

    if (!this.replacements.length) {
        return this.config.keepUnassigned ? [this.indent + this.originalContent.trim()] : [];
    }