Merge pull request #1666 from Karry/sign-compare-warn

fix sign-compare warning

Author: Framstag

libosmscout-map-opengl/src/osmscoutmapopengl/MapPainterOpenGL.cpp

@@ -247,7 +247,7 @@ namespace osmscout {
               if (fabs(p[i].GetLat() - p[j].GetLat()) < 0.000000001 &&
                   fabs(p[i].GetLon() - p[j].GetLon()) < 0.0000000001) {
                 p.erase(p.begin() + i);
-                if (i == p.size()) { // i was the last element
+                if (size_t(i) == p.size()) { // i was the last element
                   break;
                 }
               }