Revert custom theme name replace handler.

The existing handler should be able to handle it just fine already.

See c6886ab.

plugins/underscoresme-generator/underscoresme-generator.php

@@ -186,7 +186,6 @@ function do_replacements( $contents, $filename ) {
 				$contents = preg_replace( '/(' . preg_quote( $key ) . ':)\s?(.+)/', '\\1 ' . $value, $contents );
 			}
 
-			$contents = str_replace( '_s is based on Underscores', sprintf( '%s is based on Underscores',  $this->theme['name'] ), $contents );
 			$contents = preg_replace( '/\b_s\b/', $this->theme['name'], $contents );
 
 			return $contents;