Fix ES build.

src/Magnum/Context.cpp

@@ -518,7 +518,9 @@ Debug operator<<(Debug debug, const Context::Flag value) {
     switch(value) {
         #define _c(value) case Context::Flag::value: return debug << "Context::Flag::" #value;
         _c(Debug)
+        #ifndef MAGNUM_TARGET_GLES
         _c(RobustAccess)
+        #endif
         #undef _c
     }
 

src/Magnum/Platform/magnum-info.cpp

@@ -142,7 +142,11 @@ MagnumInfo::MagnumInfo(const Arguments& arguments): Platform::WindowlessApplicat
     Debug() << "OpenGL version:" << c->version() << '(' + c->versionString() + ')';
 
     Debug() << "Context flags:";
+    #ifndef MAGNUM_TARGET_GLES
     for(const auto flag: {Context::Flag::Debug, Context::Flag::RobustAccess})
+    #else
+    for(const auto flag: {Context::Flag::Debug})
+    #endif
         if(c->flags() & flag) Debug() << "   " << flag;
 
     Debug() << "Supported GLSL versions:";