Use GL_LINE_STRIP instead of GL_LINES when drawing polylines.

drivers/gles3/rasterizer_canvas_gles3.cpp

@@ -566,7 +566,7 @@ void RasterizerCanvasGLES3::_canvas_item_render_commands(Item *p_item, Item *cur
 
 					} else {
 
-						_draw_generic(GL_LINES, pline->lines.size(), pline->lines.ptr(), NULL, pline->line_colors.ptr(), pline->line_colors.size() == 1);
+						_draw_generic(GL_LINE_STRIP, pline->lines.size(), pline->lines.ptr(), NULL, pline->line_colors.ptr(), pline->line_colors.size() == 1);
 					}
 
 #ifdef GLES_OVER_GL