Revert "Remove tlsEmulation enabled from Windows + GCC config (#19119) [backport:1.6]"

This reverts commit 77b696c.

Author: ringabout

config/nim.cfg

@@ -169,6 +169,9 @@ nimblepath="$home/.nimble/pkgs/"
 # Configuration for the GNU C/C++ compiler:
 @if windows:
   #gcc.path = r"$nim\dist\mingw\bin"
+  @if gcc or tcc:
+    tlsEmulation:on
+  @end
 @end
 
 gcc.maxerrorsimpl = "-fmax-errors=3"