Update EIP-627: fix minor typo (ethereum#9830)

Update EIP-627.md: fix minor typo

Author: GarmashAlex

EIPS/eip-627.md

@@ -165,7 +165,7 @@ Symmetric encryption uses AES GCM algorithm with random 96-bit nonce.
 
 Packet codes 0x00 and 0x01 are already used in all Whisper versions.
 
-Packet code 0x02 will be necessary for the future development of Whisper. It will provide possiblitity to adjust the PoW requirement in real time. It is better to allow the network to govern itself, rather than hardcode any specific value for minimal PoW requirement.
+Packet code 0x02 will be necessary for the future development of Whisper. It will provide possibility to adjust the PoW requirement in real time. It is better to allow the network to govern itself, rather than hardcode any specific value for minimal PoW requirement.
 
 Packet code 0x03 will be necessary for scalability of the network. In case of too much traffic, the nodes will be able to request and receive only the messages they are interested in.