Updates offsets for Ethereum rfc003 htlcs

[D4nte]

Correct offsets are:

### RFC003 ###
** Ether on Ethereum **
Contract template:
 6100dc61000f6000396100dc6000f336156051576020361415605c57602060006000376020602160206000600060026048f17f1000000000000000000000000000000000000000000000000000000000000001602151141660625760006000f35b42632000000210609f575b60006000f35b7fb8cac300e37f03ad332e581dea21b2f0b84eaaadc184a295fef71e81f44a741360206000a1733000000000000000000000000000000000000003ff5b7f5d26862916391bf49478b2f5103b0720a842b45ef145a268f2cd1fb2aed5517860006000a1734000000000000000000000000000000000000004ff
| Data | Byte Range | Length (bytes) |
|:--- |:--- |:--- |
| `secret_hash` | 51..83 | 32 |
| `expiry` | 99..103 | 4 |
| `redeem_identity` | 153..173 | 20 |
| `refund_identity` | 214..234 | 20 |
** ERC20 on Ethereum **
Contract template:
 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
| Data | Byte Range | Length (bytes) |
|:--- |:--- |:--- |
| `secret_hash` | 53..85 | 32 |
| `expiry` | 102..106 | 4 |
| `redeem_identity` | 157..177 | 20 |
| `refund_identity` | 224..244 | 20 |
| `token_quantity` | 261..293 | 32 |
| `token_contract` | 307..327 | 20 |

The hex above contains placeholders (100...001) which we do not have but now want in the RFC.
Hence, update the RFC consequently.
However, the terminal ff is missing from the Ether Basic RFC and should be added.