Allow all content types on Iceshrimp

It's disabled anyways for new users, and allowing all lowers the chance
of crashes from a previously selected option being missing

mastodon/src/main/java/org/joinmastodon/android/model/ContentType.java

@@ -34,8 +34,6 @@ public enum ContentType {
 	}
 
 	public boolean supportedByInstance(Instance i) {
-		if(i.isIceshrimp())
-			return this==MISSKEY_MARKDOWN || this==UNSPECIFIED;
-		return i.isAkkoma() || (this!=BBCODE && this!=MISSKEY_MARKDOWN);
+		return i.isAkkoma() || i.isIceshrimp() || (this!=BBCODE && this!=MISSKEY_MARKDOWN);
 	}
 }