requesthandler: Fix resolution of screenshots of cropped sources

This applies the same fix found in obsproject/obs-studio#10077 to get
the target source's real width and height, not the width and height
values from the pre-filter stage.

Closes #1213

src/requesthandler/RequestHandler_Sources.cpp

@@ -28,8 +28,8 @@ with this program. If not, see <https://www.gnu.org/licenses/>
 QImage TakeSourceScreenshot(obs_source_t *source, bool &success, uint32_t requestedWidth = 0, uint32_t requestedHeight = 0)
 {
 	// Get info about the requested source
-	const uint32_t sourceWidth = obs_source_get_base_width(source);
-	const uint32_t sourceHeight = obs_source_get_base_height(source);
+	const uint32_t sourceWidth = obs_source_get_width(source);
+	const uint32_t sourceHeight = obs_source_get_height(source);
 	const double sourceAspectRatio = ((double)sourceWidth / (double)sourceHeight);
 
 	uint32_t imgWidth = sourceWidth;