Interrupt flag fix (#3974)

# About the pull request

Number was already taken.

# Explain why it's good for the game

Bug bad


# Testing Photographs and Procedure
<details>
<summary>Screenshots & Videos</summary>

Put screenshots and videos here with an empty line between the
screenshots and the `<details>` tags.

</details>


# Changelog
:cl: ihatethisengine
fix: fixed behavior_immobile flag using wrong number
/:cl:

code/__DEFINES/misc.dm

@@ -113,7 +113,7 @@
 // These behaviors are either of the person performing the action or any targets.
 
 /// You cannot move the person while this action is being performed
-#define BEHAVIOR_IMMOBILE (1<<18)
+#define BEHAVIOR_IMMOBILE (1<<19)
 
 // *************************************** //
 //    END DO_AFTER FLAGS //