Fixes GCC 8 warning:
dll/3rdparty/libxslt/security.c:358:5: error: this 'else' clause does not guard... [-Werror=misleading-indentation]
else
^~~~
dll/3rdparty/libxslt/security.c:365:2: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'else'
if (ret <= 0) {
^~
There is no need to compile our DLLs as shared libraries since we are
managing symbols exports and imports through spec files.
On my system, this reduces the configure-time by a factor of two.
