No (more?) reason for SD_DLLIMPLEMENTATION in CppunitTest_sd_uimpress

IIRC, this was a quirk with the old build system, dutifully carried across.

Change-Id: Ia66fe04666472a37bdb5f044aa7db09bb337e5eb

sd/CppunitTest_sd_uimpress.mk

@@ -32,10 +32,6 @@ $(eval $(call gb_CppunitTest_set_include,sd_uimpress,\
     -I$(SRCDIR)/sd/inc \
 ))
 
-$(eval $(call gb_CppunitTest_add_defs,sd_uimpress,\
-    -DSD_DLLIMPLEMENTATION \
-))
-
 $(eval $(call gb_CppunitTest_use_api,sd_uimpress,\
     offapi \
     udkapi \