Fix study9 mesh

examples/thermal_edge_flow/study9.geo

@@ -124,7 +124,7 @@ Curve Loop(3208) = {2301:2312};
 Plane Surface(4207) = {3207, 3208};
 Curve Loop(3209) = {2105, 2106, 2101, 2102, 2103, 2104};
 Curve Loop(3210) = {2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2001};
-Plane Surface(4209) = {3209, 3210};
+Plane Surface(4209) = {3210, 3209};
 Curve Loop(3211) = {2102, 2103, 2104, 2105, 2401, 2402};
 Plane Surface(4210) = {3211};
 Curve Loop(3212) = {2101, -2402, -2401, 2106};