Avoid unused variable warning in wxUSE_VALIDATORS==0 build.

Closes #16076.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@76140 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/propgrid/propgrid.cpp

@@ -211,15 +211,13 @@ wxPGGlobalVarsClass::wxPGGlobalVarsClass()
 
 wxPGGlobalVarsClass::~wxPGGlobalVarsClass()
 {
-    size_t i;
-
     delete m_defaultRenderer;
 
     // This will always have one ref
     delete m_fontFamilyChoices;
 
 #if wxUSE_VALIDATORS
-    for ( i=0; i<m_arrValidators.size(); i++ )
+    for ( size_t i = 0; i < m_arrValidators.size(); i++ )
         delete ((wxValidator*)m_arrValidators[i]);
 #endif