Bug 1091377 - Don't use -static-libstdc++ when building with stlport. r=mshal

It turns out that while it may have been needed at the time it was added (which,
retrospectively, I'm not even sure was the case), it definitely isn't needed
anymore.

build/stlport/moz.build

@@ -9,9 +9,6 @@ Library('stlport')
 # name for the Library for convenience in moz.build.
 STATIC_LIBRARY_NAME = 'stlport_static'
 
-if not CONFIG['MOZ_WIDGET_TOOLKIT'] == 'gonk':
-    OS_LIBS += ['-static-libstdc++']
-
 FORCE_STATIC_LIB = True
 
 SOURCES += [