Remove all use of the assert.h header

Nothing in Tor has actually called assert() for some while.

src/tools/tor-gencert.c

@@ -33,7 +33,6 @@ ENABLE_GCC_WARNING(redundant-decls)
 #if 0
 #include <stdlib.h>
 #include <stdarg.h>
-#include <assert.h>
 #endif
 
 #include "common/util.h"

src/tools/tor-resolve.c

@@ -14,7 +14,6 @@
 #include <stdlib.h>
 #include <stdarg.h>
 #include <string.h>
-#include <assert.h>
 
 #ifdef HAVE_NETINET_IN_H
 #include <netinet/in.h>