Remove "is_debug_build.inc" and use already existing "have-debug.inc"

mysql-test/include/is_debug_build.inc

--- require r/is_debug_build.require
---disable_query_log
-select instr(version(), "debug") > 0;
---enable_query_log

mysql-test/t/sp-code.test

@@ -2,7 +2,7 @@
 # Test the debugging feature "show procedure/function code <name>" 
 #
 
--- source include/is_debug_build.inc
+-- source include/have_debug.inc
 
 --disable_warnings
 drop procedure if exists empty;