testgdate: fix -Wmisleading-indentation warning

No behavior changes. Just reindent the existing code to avoid a GCC
warning spam.

I considered changing the code to not run fflush() on every iteration of
the loop, but I doubt it matters much, so I left it be.

tests/testgdate.c

@@ -27,7 +27,9 @@ if (failed) \
   } \
 else \
   ++passed;    \
-  if ((passed+notpassed) % 10000 == 0) g_print ("."); fflush (stdout); \
+if ((passed+notpassed) % 10000 == 0) \
+  g_print ("."); \
+fflush (stdout); \
 } G_STMT_END
 
 static void