Yet another minor typo in the PCP configuration files

pcp/meters/mysql

@@ -37,7 +37,7 @@ created.label = cr
 created.color = yellow
 read.metric = mysql.status.innodb_pages_read
 read.label = rd
-read.color = greed
+read.color = green
 written.metric = mysql.status.innodb_pages_written
 written.label = wr
 written.color = red