Bump use_specs to R13B04 or later

Author: Matthew Sackman

Makefile

@@ -41,10 +41,10 @@ RABBIT_PLT=rabbit.plt
 
 ifndef USE_SPECS
 # our type specs rely on features and bug fixes in dialyzer that are
-# only available in R13B01 upwards (R13B01 is eshell 5.7.2)
+# only available in R13B04 upwards (R13B04 is erts 5.7.5)
 #
 # NB: the test assumes that version number will only contain single digits
-USE_SPECS=$(shell if [ $$(erl -noshell -eval 'io:format(erlang:system_info(version)), halt().') \> "5.7.1" ]; then echo "true"; else echo "false"; fi)
+USE_SPECS=$(shell if [ $$(erl -noshell -eval 'io:format(erlang:system_info(version)), halt().') \> "5.7.4" ]; then echo "true"; else echo "false"; fi)
 endif
 
 #other args: +native +"{hipe,[o3,verbose]}" -Ddebug=true +debug_info +no_strict_record_tests