Fix upsc data retrieval (#126)

pve-mod-gui-sensors.sh

@@ -440,16 +440,24 @@ collect_ups_output() {
     else
         ups_cmd="upsc \"$upsConnection\" 2>/dev/null"
     fi
+
     # region ups heredoc
     sed -i "/my \$dinfo = df('\/', 1);/i\\
 \\
 # Collect UPS status information\\
-		\$res->{upsc} = \\\`$ups_cmd\\\`;\\
+sub get_upsc {\\
+    my \$cmd = '$ups_cmd';\\
+    my \$output = \`\\\$cmd\`;\\
+    return \$output;\\
+}\\
+\$res->{upsc} = get_upsc();\\
 " "$NODES_PM_FILE"
     # endregion ups heredoc
+
     info "UPS retriever added to \"$output_file\"."
 }
 
+
 # Collect system information
 collect_system_info() {
     local output_file="$1"