firebird: enable-debug cause trouble due to a lifecycle management issue

firebird in debug mode abort() on lo shutdown due to a lifcycle management
issue where firebord try to create a directory in a temp directory that
is not there anymore, and then exception for it and
that exception in debug mode cause an abort.

Change-Id: Iabbd6ffda34a84e5b0d8e44761226083c8c1d168

external/firebird/ExternalProject_firebird.mk

@@ -50,7 +50,6 @@ $(call gb_ExternalProject_get_state_target,firebird,build):
 			--without-editline \
 			--disable-superserver \
 			--with-system-icu --without-fbsample --without-fbsample-db \
-			$(if $(filter TRUE,$(ENABLE_DEBUG)),--enable-debug) \
 			$(if $(CROSS_COMPILING),--build=$(BUILD_PLATFORM) --host=$(HOST_PLATFORM)) \
 			$(if $(filter IOS ANDROID,$(OS)),--disable-shared,--disable-static) \
 		&& $(if $(filter WNT,$(OS)),\