Remove changes files already merged in release-0.4.5

changes/bug40256_045

-  o Minor bugfixes (documentation):
-    - Fix a formatting error on the documentation for
-      VirtualAddrNetworkIPv6.  Fixes bug 40256; bugfix on 0.2.9.4-alpha.

changes/bug40315

-  o Minor bugfixes (Linux, relay):
-    - Fix a bug in determining total available system memory that would have
-      been triggered if the format of /proc/meminfo had ever changed
-      to include "MemTotal:" in the middle of a line. Fixes bug 40315;
-      bugfix on 0.2.5.4-alpha.

changes/ticket40334

-  o Minor bugfixes (onion service):
-    - Remove a harmless BUG() warning when reloading tor configured with onion
-      services. Fixes bug 40334; bugfix on 0.4.5.1-alpha.