Fix quotes (grmpf)

I noticed an Oops.
opt_es:"-L ISO-8859-1"    -A utf-8       \
it's outside quotes. Doesn't throw any error, just doesn't do its job.

man/po/po4a.cfg

@@ -4,7 +4,7 @@
 # Make sure the man pages are generated with the right encoding.
 [po4a_alias:man] man                                      \
                  opt_de:"-L ISO-8859-1"                   \
-                 opt_es:"-L ISO-8859-1"    -A utf-8       \
+                 opt_es:"-L ISO-8859-1     -A utf-8"      \
                  opt_fr:"-L ISO-8859-1"                   \
                  opt_hu:"-L ISO-8859-2     -A ISO-8859-2" \
                  opt_ja:"-L euc-jp         -A utf-8"      \