treewide: remove uses of doBuild and doConfigure

doBuild and doConfigure are not actually used by any builders, they were
probably added by mistake and just confuse people.

pkgs/servers/xmpp/pyIRCt/default.nix

@@ -15,7 +15,6 @@ stdenv.mkDerivation rec {
     xmpppy pythonIRClib
   ];
 
-  /* doConfigure should be removed if not needed */
   # phaseNames = ["deploy" (a.makeManyWrappers "$out/share/${name}/irc.py" a.pythonWrapperArguments)];
 
   installPhase = ''

pkgs/servers/xmpp/pyMAILt/default.nix

@@ -14,7 +14,6 @@ stdenv.mkDerivation rec {
   pythonPath = [ xmpppy ];
   buildInputs = [ pythonPackages.wrapPython ];
 
-  /* doConfigure should be removed if not needed */
   installPhase = ''
     cd mail-transport
     mkdir -p $out/bin $out/share/${pname}-${version}