Fix spacing.

Author: yruslan

project/plugins.sbt

@@ -16,5 +16,5 @@
 
 addSbtPlugin("com.jsuereth"      % "sbt-pgp"       % "2.0.0")
 addSbtPlugin("com.github.gseitz" % "sbt-release"   % "1.0.12")
-addSbtPlugin("de.heikoseeberger" % "sbt-header" % "5.6.0")
+addSbtPlugin("de.heikoseeberger" % "sbt-header"    % "5.6.0")