Hack-fix build with different system/core/charger versions

Signed-off-by: Vojtech Bocek <vbocek@gmail.com>
diff --git a/minui/graphics.c b/minui/graphics.c
index 4968eac..9ee77b3 100644
--- a/minui/graphics.c
+++ b/minui/graphics.c
@@ -223,7 +223,12 @@
     *y = gr_font->cheight;
 }
 
-int gr_text(int x, int y, const char *s, int bold)
+int gr_text(int x, int y, const char *s, ...)
+{
+    return gr_text_impl(x, y, s, 0);
+}
+
+int gr_text_impl(int x, int y, const char *s, int bold)
 {
     GGLContext *gl = gr_context;
     GRFont *font = gr_font;
diff --git a/minui/minui.h b/minui/minui.h
index 1b8dd05..ccd501f 100644
--- a/minui/minui.h
+++ b/minui/minui.h
@@ -37,7 +37,12 @@
 
 void gr_color(unsigned char r, unsigned char g, unsigned char b, unsigned char a);
 void gr_fill(int x1, int y1, int x2, int y2);
-int gr_text(int x, int y, const char *s, int bold);
+
+// system/core/charger uses different gr_print signatures in diferent
+// Android versions, either with or without int bold.
+int gr_text(int x, int y, const char *s, ...);
+int gr_text_impl(int x, int y, const char *s, int bold);
+
  void gr_texticon(int x, int y, gr_surface icon);
 int gr_measure(const char *s);
 void gr_font_size(int *x, int *y);