filter characters in upstream nicks, to just alphanumeric

NTFServer.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"html"
 	"log"
+	"regexp"
 	"sort"
 	"strings"
 	"sync"
@@ -545,6 +546,9 @@ func (this *NTFServer) HandleDirectMessage(update telegram.Update) error {
 	} else if strings.HasPrefix(msg, "/join ") {
 		requestedHubNick := msg[6:]
 
+		// Some users take the [] in the message literally. A-Za-z0-9 are the only supported characters
+		requestedHubNick = regexp.MustCompile(`[^a-zA-Z0-9]`).ReplaceAllString(requestedHubNick, "")
+
 		// Minimum nick lengths
 		if len(requestedHubNick) < this.config.HubNickMinChars {
 			return respond(fmt.Sprintf("Upstream nickname '%s' should be at least %d characters long", requestedHubNick, this.config.HubNickMinChars))