Remove -fsanitize=leak for Mac compat

Should bring it back if/when we use a smarter build guy

Makefile

@@ -1,6 +1,7 @@
 basic_flags := -std=c99 -pipe -Wall -Wpedantic -Wextra -Werror=implicit-function-declaration
 debug_flags := -DDEBUG -O0 -ggdb -feliminate-unused-debug-symbols
-sanitize_flags := -fsanitize=address -fsanitize=leak -fsanitize=undefined
+sanitize_flags := -fsanitize=address -fsanitize=undefined
+# note: -fsanitize=leak not available on at least Mac 10.12
 release_flags := -DNDEBUG -O2 -s -D_FORTIFY_SOURCE=2 -fstack-protector-strong -fpie -Wl,-pie
 library_flags := -lncurses
 source_files := field.c main.c