Fix -Wuninitialized warnings.

configure.ac

 
 AX_CHECK_COMPILE_FLAG([-Wmissing-prototypes],    [CFLAGS="-Wmissing-prototypes $CFLAGS"])
 AX_CHECK_COMPILE_FLAG([-Wreturn-type],           [CFLAGS="-Wreturn-type $CFLAGS"])
+AX_CHECK_COMPILE_FLAG([-Wuninitialized],         [CFLAGS="-Wuninitialized $CFLAGS"])
 AX_CHECK_COMPILE_FLAG([-Wunused],                [CFLAGS="-Wunused $CFLAGS"])
 AX_CHECK_COMPILE_FLAG([-Wunused-parameter],      [CFLAGS="-Wunused-parameter $CFLAGS"])
 

src/libespeak-ng/compiledata.c

 	int done_onset = 0;
 	int done_last = 0;
 	int n_preset_tunes = 0;
-	int found;
+	int found = 0;
 	int tune_number = 0;
 	FILE *f_out;
 	TUNE *tune_data;