fixed minor issues causing civirules to break

CRM/Civirules/Delay/XWeekDay.php

@@ -13,7 +13,7 @@ class CRM_Civirules_Delay_XWeekDay extends CRM_Civirules_Delay_Delay {
   public function delayTo(DateTime $date) {
     $d = clone $date;
     $d->modify('-30 minutes');
-    $mod = $this->day.' of this week';
+    $mod = $this->day.' this week';
     $date->modify($mod);
     $date->setTime((int) $this->time_hour, (int) $this->time_minute);
     if ($date <= $d) {

CRM/CivirulesConditions/FieldValueComparison.php

@@ -37,7 +37,7 @@ class CRM_CivirulesConditions_FieldValueComparison extends CRM_CivirulesConditio
   }
 
   protected function normalizeValue($value) {
-    if (value === null) {
+    if ($value === null) {
       return null;
     }
 

CRM/CivirulesConditions/Utils/Period.php

@@ -252,7 +252,7 @@ class CRM_CivirulesConditions_Utils_Period {
    */
   public static function convertPeriodToStartDate($condition_params) {
     $period = $condition_params['period'];
-    $replaceParameters = $condition_params['replaceParameters'];
+    $replaceParameters = isset($condition_params['replaceParameters']) ? $condition_params['replaceParameters'] : array();
     $date = new DateTime();
     switch ($period) {
       case 'this month':
@@ -317,7 +317,7 @@ class CRM_CivirulesConditions_Utils_Period {
    */
   public static function convertPeriodToEndDate($condition_params) {
     $period = $condition_params['period'];
-    $replaceParameters = $condition_params['replaceParameters'];
+    $replaceParameters = isset($condition_params['replaceParameters']) ? $condition_params['replaceParameters'] : array();
     $date = new DateTime();
     switch ($period) {
       case 'this month':