Replaced the `*.toml` pattern in `.gitignore` by something more specific

This pattern was actually only here for `gargantext-settings.toml`, but
other `.toml` files should not be ignored by default

.gitignore

@@ -34,7 +34,7 @@ _darcs
 *.pdf
 *.png
 *.ini
-*.toml
+gargantext-settings.toml
 !test-data/test_config.ini
 
 # Runtime