Revert "build: enable Boost.MultiIndex safe mode in debug builds"

This reverts commit 80f6755ab06cf3a382c90a89383328a5c84f3dfb, which
was causing random/nonsensical crashes in dependent projects when
mixing debug and release builds (I assume because safe mode changes
the ABI).

Change-Id: Ie9d039939f18ae3e04ca27816b7c30433ab3974c
diff --git a/.waf-tools/default-compiler-flags.py b/.waf-tools/default-compiler-flags.py
index a765b4d..e412692 100644
--- a/.waf-tools/default-compiler-flags.py
+++ b/.waf-tools/default-compiler-flags.py
@@ -133,12 +133,7 @@
         return {
             'CXXFLAGS': [],
             'LINKFLAGS': [],
-            'DEFINES': [
-                'BOOST_ASIO_NO_DEPRECATED',
-                'BOOST_FILESYSTEM_NO_DEPRECATED',
-                'BOOST_MULTI_INDEX_ENABLE_INVARIANT_CHECKING',
-                'BOOST_MULTI_INDEX_ENABLE_SAFE_MODE',
-            ],
+            'DEFINES': ['BOOST_ASIO_NO_DEPRECATED', 'BOOST_FILESYSTEM_NO_DEPRECATED'],
         }
 
     def getOptimizedFlags(self, conf):