add OpenBSD, so that strcasecmp is used

Index: game/anim/Anim_Blend.cpp
--- game/anim/Anim_Blend.cpp.orig
+++ game/anim/Anim_Blend.cpp
@@ -3666,7 +3666,7 @@ bool idDeclModelDef::Parse( const char *text, const in
 			}
 
 			for( i = ANIMCHANNEL_ALL + 1; i < ANIM_NumAnimChannels; i++ ) {
-#if MACOS_X || __linux__
+#if MACOS_X || __linux__ || __OpenBSD__
 				if ( !strcasecmp( channelNames[ i ], token2.c_str() ) )
 #else
 				if ( !stricmp( channelNames[ i ], token2.c_str() ) )
