manager: configure as only for termux

manager.sh

@@ -56,7 +56,7 @@ download()
 	fi
 
 	echo "Extracting..."
-	if ! unzip -d $PREFIX/tmp $PREFIX/tmp/pmt.zip &>/dev/null; then
+	if ! unzip -f -d $PREFIX/tmp $PREFIX/tmp/pmt.zip &>/dev/null; then
 		echo "Extraction failed!"
 		exit 1
 	fi
@@ -97,6 +97,11 @@ if [ $# -eq 0 ]; then
     exit 1
 fi
 
+if ! basename -a ${PREFIX}/bin/* | grep "termux" &>/dev/null; then
+	echo "This script only for termux!"
+	exit 1
+fi
+
 case $1 in
     "install")
     	is_installed