Add versioned so files extension to Qt.gitignore (#3186)

Some Qt packages builds versioned shared objects which will generate foobar.so.n symlinks to the output file. These files should not tracked by git.

Qt.gitignore

@@ -6,6 +6,7 @@
 *.la
 *.lai
 *.so
+*.so.*
 *.dll
 *.dylib