Fix user search when using an asterisk (#4586)

store/sql_user_store.go

@@ -1217,11 +1217,24 @@ func (us SqlUserStore) SearchInChannel(channelId string, term string, options ma
 	return storeChannel
 }
 
+var specialUserSearchChar = []string{
+	"<",
+	">",
+	"+",
+	"-",
+	"(",
+	")",
+	"~",
+	"@",
+	":",
+	"*",
+}
+
 func (us SqlUserStore) performSearch(searchQuery string, term string, options map[string]bool, parameters map[string]interface{}) StoreResult {
 	result := StoreResult{}
 
 	// these chars have special meaning and can be treated as spaces
-	for _, c := range specialSearchChar {
+	for _, c := range specialUserSearchChar {
 		term = strings.Replace(term, c, " ", -1)
 	}