MAINT-2155: re-remove remnants of mac_updater source subtree.

Merging up to viewer-development brought in additional mac_updater sources.
Delete them along with the rest.

indra/mac_updater/AutoUpdater.nib/objects.xib

-<?xml version="1.0" standalone="yes"?>
-<object class="NSIBObjectData">
-  <string name="targetFramework">IBCarbonFramework</string>
-  <object name="rootObject" class="NSCustomObject" id="1">
-    <string name="customClass">NSApplication</string>
-  </object>
-  <array count="5" name="allObjects">
-    <object class="IBCarbonWindow" id="166">
-      <string name="windowRect">405 222 533 663 </string>
-      <string name="title">Second Life Updater</string>
-      <object name="rootControl" class="IBCarbonRootControl" id="167">
-        <string name="bounds">0 0 128 441 </string>
-        <array count="3" name="subviews">
-          <object class="IBCarbonStaticText" id="181">
-            <string name="bounds">20 20 44 421 </string>
-            <ostype name="controlSignature">what</ostype>
-            <string name="title">Initializing…</string>
-          </object>
-          <object class="IBCarbonButton" id="183">
-            <string name="bounds">88 351 108 421 </string>
-            <string name="title">Cancel</string>
-            <ostype name="command">not!</ostype>
-            <int name="buttonType">2</int>
-          </object>
-          <object class="IBCarbonProgressBar" id="193">
-            <string name="bounds">51 19 70 422 </string>
-            <ostype name="controlSignature">prog</ostype>
-            <int name="initialValue">50</int>
-          </object>
-        </array>
-      </object>
-      <boolean name="isResizable">FALSE</boolean>
-      <int name="carbonWindowClass">2</int>
-      <int name="themeBrush">3</int>
-      <int name="windowPosition">7</int>
-    </object>
-    <reference idRef="167"/>
-    <reference idRef="181"/>
-    <reference idRef="183"/>
-    <reference idRef="193"/>
-  </array>
-  <array count="5" name="allParents">
-    <reference idRef="1"/>
-    <reference idRef="166"/>
-    <reference idRef="167"/>
-    <reference idRef="167"/>
-    <reference idRef="167"/>
-  </array>
-  <dictionary count="2" name="nameTable">
-    <string>File&apos;s Owner</string>
-    <reference idRef="1"/>
-    <string>Updater</string>
-    <reference idRef="166"/>
-  </dictionary>
-  <unsigned_int name="nextObjectID">194</unsigned_int>
-</object>