Fix uninitialized FontGlyph fields in FontFaceBitmap (closes #2035)

Commit 0450bcd1 added two extra fields to FontGlyph, texWidth_ and texHeight_,
but these weren't being initialized for bitmap fonts.

Bitmap text would sometimes randomly look OK if the uninitialized fields
contained large numbers, and fail if the fields contained zeroes.

Source/Urho3D/UI/FontFaceBitmap.cpp

@@ -133,8 +133,8 @@ bool FontFaceBitmap::Load(const unsigned char* fontData, unsigned fontDataSize,
         FontGlyph glyph;
         glyph.x_ = (short)charElem.GetInt("x");
         glyph.y_ = (short)charElem.GetInt("y");
-        glyph.width_ = (short)charElem.GetInt("width");
-        glyph.height_ = (short)charElem.GetInt("height");
+        glyph.width_ = glyph.texWidth_ = (short)charElem.GetInt("width");
+        glyph.height_ = glyph.texHeight_ = (short)charElem.GetInt("height");
         glyph.offsetX_ = (short)charElem.GetInt("xoffset");
         glyph.offsetY_ = (short)charElem.GetInt("yoffset");
         glyph.advanceX_ = (short)charElem.GetInt("xadvance");