fixing OS/2 bustage from string branch landing,

nsString.h needs to continue to define IGNORE_CASE for backwards compatibility

xpcom/string/public/nsString.h

@@ -64,6 +64,7 @@
 #define kRadix16        (16)
 #define kAutoDetect     (100)
 #define kRadixUnknown   (kAutoDetect+1)
+#define IGNORE_CASE     (PR_TRUE)
 #endif
 
 class CBufDescriptor;