Updated version number to 1.10.8 in man page.

doc/aria2c.1.asciidoc

@@ -3,7 +3,7 @@ ARIA2C(1)
 Tatsuhiro Tsujikawa <[email protected]>
 :man source: Aria2
 :man manual: Aria2 Manual
-:man version: 1.10.7
+:man version: 1.10.8
 
 NAME
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