Bug 258804 It tries to build Dogbert for BeOS and it's not needed

patch by fvincent@bol.com.br r=sergei_d sr=mscott

mail/components/migration/src/Makefile.in

@@ -35,9 +35,12 @@ CPPSRCS = \
 	nsMailProfileMigratorUtils.cpp \
 	nsNetscapeProfileMigratorBase.cpp \
 	nsSeamonkeyProfileMigrator.cpp \
-	nsDogbertProfileMigrator.cpp \
 	$(NULL)
 
+ifneq ($(OS_ARCH),BeOS)
+CPPSRCS += nsDogbertProfileMigrator.cpp
+endif
+
 ifeq ($(OS_ARCH),WINNT)
 CPPSRCS += \
 	nsProfileMigratorBase.cpp \