doc/ircd: rename pubkey to contact_public on ircd Contact specification

doc/src/misc/ircd/specification.md

@@ -41,7 +41,7 @@ In the TOML configuration file, the contact is set as such:
 
 ```toml
 [contact."nick"]
-pubkey = "7CkVuFgwTUpJn5Sv67Q3fyEDpa28yrSeL5Hg2GqQ4jfM"
+contact_pubkey = "7CkVuFgwTUpJn5Sv67Q3fyEDpa28yrSeL5Hg2GqQ4jfM"
 ```
 
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