Update EIP-1015: Fix typo (#8331)

fix typos

EIPS/eip-1015.md

@@ -20,7 +20,7 @@ These are current EIPs that are being developed or debated. They might seem unre
 
 #### Casper and PoS
 
-Moving to PoS has been on the roadmap since day 0 for ethereum, along with a reduction in issuance to a cost equivalent to the Validator's cost of security (considered to be more eficient than PoW). But the exact issuance necessary for PoS has yet to be determined and is currently being researched. Casper validation will be an on chain contract and therefore it will need to be funded. It's unlikely that a definitive final answer on how much issuance is needed for validation will be reached in the next years as new research will uncover new arguments, so it would make sense to allow some flexibility on this matter
+Moving to PoS has been on the roadmap since day 0 for ethereum, along with a reduction in issuance to a cost equivalent to the Validator's cost of security (considered to be more efficient than PoW). But the exact issuance necessary for PoS has yet to be determined and is currently being researched. Casper validation will be an on chain contract and therefore it will need to be funded. It's unlikely that a definitive final answer on how much issuance is needed for validation will be reached in the next years as new research will uncover new arguments, so it would make sense to allow some flexibility on this matter
 
 #### Issuance Cap at 120 Million