Fix some warnings reported from msvc

simgear/io/HTTPRepository.cxx

@@ -253,7 +253,7 @@ public:
               // already exists on disk
               parseDirIndex(children);
               std::sort(children.begin(), children.end());
-          } catch (sg_exception& e) {
+          } catch (sg_exception& ) {
               // parsing cache failed
               children.clear();
           }
@@ -775,7 +775,7 @@ HTTPRepository::failure() const
                     st.stamp();
                     _directory->updateChildrenBasedOnHash();
                     SG_LOG(SG_TERRASYNC, SG_INFO, "after update of:" << _directory->absolutePath() << " child update took:" << st.elapsedMSec());
-                } catch (sg_exception& e) {
+                } catch (sg_exception& ) {
                     _directory->failedToUpdate(AbstractRepository::REPO_ERROR_IO);
                 }
             } else if (responseCode() == 404) {

simgear/package/Catalog.cxx

@@ -119,7 +119,7 @@ protected:
         try {
             readProperties(m_buffer.data(), m_buffer.size(), props);
             m_owner->parseProps(props);
-        } catch (sg_exception& e) {
+        } catch (sg_exception& ) {
             SG_LOG(SG_GENERAL, SG_ALERT, "catalog parse failure:" << m_owner->url());
             m_owner->refreshComplete(Delegate::FAIL_EXTRACT);
             return;
@@ -207,7 +207,7 @@ CatalogRef Catalog::createFromPath(Root* aRoot, const SGPath& aPath)
     try {
         props = new SGPropertyNode;
         readProperties(xml.str(), props);
-    } catch (sg_exception& e) {
+    } catch (sg_exception& ) {
         return NULL;
     }
 

simgear/package/Install.cxx

@@ -273,7 +273,7 @@ private:
                     throw sg_io_exception("failed to go to next file in the archive");
                 }
             }
-        } catch (sg_exception& e) {
+        } catch (sg_exception& ) {
             result = false;
         }
 

simgear/package/Package.cxx

@@ -142,7 +142,7 @@ InstallRef Package::existingInstall(const InstallCallback& cb) const
     InstallRef install;
     try {
         install = m_catalog->root()->existingInstallForPackage(const_cast<Package*>(this));
-    } catch (std::exception& e) {
+    } catch (std::exception& ) {
         return InstallRef();
     }