luci-base: cbi.js: collapse whitespace before language string hashing

To mirror the behavior of the Lua runtime, we need to collapse whitepace
in translation source strings before doing the string table lookup.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>
(cherry picked from commit aca2c4ba4e)

modules/luci-base/htdocs/luci-static/resources/cbi.js

@@ -95,7 +95,7 @@ function sfh(s) {
 }
 
 function _(s) {
-	return (window.TR && TR[sfh(s)]) || s;
+	return (window.TR && TR[sfh(String(s).trim().replace(/[ \t\n]+/g, ' '))]) || s;
 }