gui2/tunit_attack: Remove trailing newline from unit stats area

Again, not visible on platforms where Pango is broken.

changelog

@@ -4,6 +4,7 @@ Version 1.13.3+dev:
  * User interface:
    * Fix vertical alignment of individual attacks listed in the Attack Unit
      dialog.
+   * Removed extra padding below unit stats in the Attack Unit dialog.
  * Miscellaneous and bug fixes:
    * Fix non-deterministic crashes in the Attack Unit dialog resulting from
      invalid memory references (regression introduced in 1.13.3).

src/gui/dialogs/unit_attack.cpp

@@ -130,7 +130,7 @@ static std::string format_stats(const unit& u)
 	str << font::span_color(u.xp_color()) 
 		<< _("XP: ") << u.experience() << "/" << u.max_experience() << "</span>" << "\n";
 
-	str << "</small>" << "\n";
+	str << "</small>";
 
 	return str.str();
 }