TangoCMakeModules: Update it with correct _WINSTATIC definitions

_WINSTATIC is an omniORB define and not actually related to Tango (see TangoCMakeModules#11 (closed)). The TangoCMakeModules update defines _WINSTATIC for the omniORB libraries so we no longer need to define it here for the tango target.

_WINSTATIC (and TANGO_HAS_DLL) are mentioned in INSTALL.md when they no longer need to be, however, I think this is being fixed in !1302 (merged) so I have left it as is here.

Closes #1294 (closed).