fix syntax error in the configure-index

The file isn't supposed to be a valid config file, but it should
show valid syntax non-the-less.

Git-Dch: Ignore

doc/examples/configure-index

@@ -225,7 +225,7 @@ Acquire
 	Verify-Peer "false";
 	SslCert "/etc/apt/some.pem";
 	CaPath  "/etc/ssl/certs";
-	Verify-Host" "true";
+	Verify-Host "true";
 	AllowRedirect  "true";
 
 	Timeout "120";