[gtk-doc] tests: add blank line after symbol name

[Stefan Sauer <stefkost src gnome org>]

commit a4d0b71c288d028a88f5bce8d4fd020e9372a8ee
Author: Stefan Sauer <ensonic users sf net>
Date:   Wed Aug 9 11:02:09 2017 +0200

    tests: add blank line after symbol name
    
    Otherwise we get partial docs and one test fails.

 tests/empty/src/tester.h |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/tests/empty/src/tester.h b/tests/empty/src/tester.h
index ed2ade6..a9f5515 100644
--- a/tests/empty/src/tester.h
+++ b/tests/empty/src/tester.h
@@ -6,6 +6,7 @@
 
 /**
  * FOO:
+ *
  * The FOO.
  *
  * Since: 0.1