Fix for crash in dac≈ when it has no input feeding it.
Fix for crash in dac≈ when it has no input feeding it.

git-svn-id: b98140ee64f7c1a7fd4934a3412a55f2e76e5e71@9 719cbc82-b2b2-11dd-9e4a-13528392d412

jamoma/JamomaCore,eriser/JamomaCore,eriser/JamomaCore,jamoma/JamomaCore,jamoma/JamomaCore,jamoma/JamomaCore,eriser/JamomaCore,jamoma/JamomaCore,jamoma/JamomaCore,eriser/JamomaCore,jamoma/JamomaCore,eriser/JamomaCore,eriser/JamomaCore,eriser/JamomaCore,eriser/JamomaCore