Fix #2530: Look for our version number in correct place.

Author: DarkDimius

compiler/src/dotty/tools/dotc/config/Properties.scala

@@ -7,7 +7,7 @@ import java.util.jar.Attributes.{ Name => AttributeName }
 
 /** Loads `library.properties` from the jar. */
 object Properties extends PropertiesTrait {
-  protected def propCategory    = "library"
+  protected def propCategory    = "compiler"
   protected def pickJarBasedOn  = classOf[Option[_]]
 
   /** Scala manifest attributes.