fix double WebGLUniforms upload for ShaderMaterial if uniformsNeedUpdate

src/renderers/WebGLRenderer.js

@@ -1982,9 +1982,7 @@ function WebGLRenderer( parameters ) {
 
 			WebGLUniforms.upload( _gl, materialProperties.uniformsList, m_uniforms, textures );
 
-		}
-
-		if ( material.isShaderMaterial && material.uniformsNeedUpdate === true ) {
+		} else if ( material.isShaderMaterial && material.uniformsNeedUpdate === true ) {
 
 			WebGLUniforms.upload( _gl, materialProperties.uniformsList, m_uniforms, textures );
 			material.uniformsNeedUpdate = false;