Cleanup sxmo_weather.sh shellscript and make sure shellcheck passes

scripts/appscripts/sxmo_weather.sh

@@ -1,5 +1,5 @@
 #!/usr/bin/env sh
-[ -z "$SXMO_WEATHERZIPS" ] && SXMO_WEATHERZIPS="
+[ -z "$SXMO_WEATHER_ZIPS" ] && SXMO_WEATHER_ZIPS="
 	10025 - NYC
 	60007 - Chicago
 	94016 - San Francisco
@@ -17,8 +17,8 @@ ZIP=$(
 pkill svkbd-sxmo
 
 LATLON="$(grep "^$ZIP" /usr/share/sxmo/zipcodes_for_weather.csv)"
-LAT=$(echo "$LATLON" | cut -d, -f2 | tr -d ' ')
-LON=$(echo "$LATLON" | cut -d, -f3 | tr -d ' ')
-URL="https://forecast.weather.gov/MapClick.php?lat=${LAT}&lon=${LON}&unit=0&lg=english&FcstType=text&TextType=1"
+LAT="$(echo "$LATLON" | cut -d, -f2 | tr -d ' ')"
+LON="$(echo "$LATLON" | cut -d, -f3 | tr -d ' ')"
+URL='https://forecast.weather.gov/MapClick.php?lat='$LAT'&lon='$LON'&unit=0&lg=english&FcstType=text&TextType=1'
 
 st -f Monospace-20 -e w3m "$URL"