Remove extra NDEBUG

Author: bmunguia

meson.build

@@ -5,7 +5,7 @@ project('SU2', 'c', 'cpp',
         license: 'LGPL2',
         default_options: ['buildtype=release',
                           'warning_level=0',
-                          'b_ndebug=true',
+                          'b_ndebug=if-release',
                           'c_std=c99',
                           'cpp_std=c++17'])
 
@@ -120,11 +120,6 @@ if get_option('enable-cgns')
   su2_cpp_args += '-DHAVE_CGNS'
 endif
 
-# check for non-debug build
-if get_option('buildtype')!='debug'
-  su2_cpp_args += '-DNDEBUG'
-endif
-
 # check for mixed precision floating point arithmetic
 if get_option('enable-mixedprec')
   su2_cpp_args += '-DUSE_MIXED_PRECISION'