fix(envcanada): set temperature to null when unavailable

Ensure current.temperature is always set (either to a value, cached value,
or null) to prevent undefined temperature in weather display.

Author: KristjanESPERANTO

defaultmodules/weather/providers/envcanada.js

@@ -161,6 +161,8 @@ class EnvCanadaProvider {
 			this.cacheCurrentTemp = current.temperature;
 		} else if (this.cacheCurrentTemp !== null) {
 			current.temperature = this.cacheCurrentTemp;
+		} else {
+			current.temperature = null;
 		}
 
 		// Wind