I would like a direct change of variable proof of the identity

$$\int_0^{\arctan\frac{\sqrt{2}}{3^{\frac{1}{4}}} \frac{1}{\sqrt{1-\frac{2+\sqrt{3}}{4}\sin^2\phi }}d\phi=\int_0^{\arctan\frac{1}{3^{\frac{1}{4}}}\frac{1}{\sqrt{1-\frac{2+\sqrt{3}}{4}\sin^22\phi }}d\phi\,.$$ I need it as part of a paper on Legendre's proof of the "third singular modulus."