winetricks_set_wineprefix: warn if binary arch is unknown

Currently if the binary arch can't be detected, w_die exits
the function winetricks_get_file_arch, but winetricks
continues. For now, only warn about this.

src/winetricks

@@ -5106,10 +5106,16 @@ winetricks_set_wineprefix()
     if test -d "${W_DRIVE_C}/windows/syswow64"; then
         # Check the bitness of wineserver + wine binary, used later to determine if we're on a WOW setup (no wine64)
         # https://github.com/Winetricks/winetricks/issues/2030
+
         WINESERVER_BIN="$(which "${WINESERVER}")"
-        _W_wineserver_binary_arch="$(winetricks_get_file_arch "${WINESERVER_BIN}")"
+        if ! _W_wineserver_binary_arch="$(winetricks_get_file_arch "${WINESERVER_BIN}")"; then
+            w_warn "Unknown file arch of ${WINESERVER_BIN}, continuing anyway."
+        fi
+
         WINE_BIN="$(which "${WINE}")"
-        _W_wine_binary_arch="$(winetricks_get_file_arch "${WINE_BIN}")"
+        if ! _W_wine_binary_arch="$(winetricks_get_file_arch "${WINE_BIN}")"; then
+            w_warn "Unknown file arch of ${WINE_BIN}, continuing anyway."
+        fi
 
         # determine wow64 type (new/old)
         # FIXME: check what upstream is calling them