debug build: build with -fsanitize=address

Let's compile with this flag to detect memory erros in the debug build.

See https://clang.llvm.org/docs/AddressSanitizer.html

Regards: #1512

configure-debug

@@ -1,4 +1,4 @@
 #!/bin/sh
 
 #./configure PYTHON_VERSION=3 CFLAGS='-g3 -O0' CXXFLAGS='-g3 -O0' $@
-./configure CFLAGS='-g3 -O0' CXXFLAGS='-g3 -O0' $@
+./configure CFLAGS='-g3 -O0 -fsanitize=address' CXXFLAGS='-g3 -O0' $@