sl_SI locale: Use "." as the thousands separator (bug 25233)

This is correct according to CLDR [1] and Florian Weimer's quick
research. [2]

[1] https://st.unicode.org/cldr-apps/v#/sl/Symbols/
[2] https://sourceware.org/bugzilla/show_bug.cgi?id=25233#c0

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>

localedata/locales/sl_SI

@@ -2134,7 +2134,7 @@ LC_MONETARY
 int_curr_symbol           "EUR "
 currency_symbol           "<U20AC>"
 mon_decimal_point         ","
-mon_thousands_sep         "<U202F>"
+mon_thousands_sep         "."
 mon_grouping              3;3
 positive_sign             ""
 negative_sign             "-"
@@ -2150,7 +2150,7 @@ END LC_MONETARY
 
 LC_NUMERIC
 decimal_point             ","
-thousands_sep             "<U202F>"
+thousands_sep             "."
 grouping                  0;0
 END LC_NUMERIC