CAPTCHA_LENGTH=0 disables captchas

Change-Id: I4c7ec6e2176019a86240bfda3cbabe3644a7afe6
diff --git a/templates/recover_email_form.htm b/templates/recover_email_form.htm
index 6560354..c0593d6 100644
--- a/templates/recover_email_form.htm
+++ b/templates/recover_email_form.htm
@@ -10,6 +10,7 @@
             value="<?php echo isset($_POST['email']) ? htmlspecialchars($_POST['email']) : '' ?>" />
     </div>
 
+    <?php if($CAPTCHA_LENGTH > 0): ?>
     <!--captcha here-->
     <div class="form-outline mb-3">
 
@@ -24,6 +25,7 @@
         <input pattern="[^\s]{<?php echo $CAPTCHA_LENGTH; ?>,}" required title="Please fill the captcha. It has 5 characters" name="captcha"
             type="text" id="form3Example6" class="form-control" placeholder="Type what you see on the image above" />
     </div>
+    <?php endif; ?>
 
     <!-- Submit button -->
     <button name="type" value="recover" type="submit" class="btn btn-primary float-right btn-md">Confirm</button>