Default flipper example should not include @program_id (#1564)

Users are getting the error "incorrect program id for instruction",
which is confusing.

Signed-off-by: Sean Young <sean@mess.org>

examples/solana/flipper.sol

@@ -1,4 +1,3 @@
-@program_id("F1ipperKF9EfD821ZbbYjS319LXYiBmjhzkkf5a26rC")
 contract flipper {
 	bool private value;