title: Dockerfile install amqp failed
body: <p>I have some issues with my dockerfile... Here is the problem, I have a dockerfile based on this image -> FROM php:7.1.7-apache</p>
  
  <p>I want to install amqp extension for php. I was using pecl but since recently when i build my container i get an error.</p>
  
  <p>Here is the process i'm using in my dockerfile </p>
  
  <pre><code>FROM php:7.1.7-apache
  
  MAINTAINER T3ddy &lt;xx@xxx.com&gt;
  
  RUN apt-get update
  
  ## TOOLS
  RUN apt-get install -y \
      build-essential \
      curl \
      git \
      htop \
      ncdu \
      netcat \
      net-tools \
      telnet \
      unzip \
      vim \
      wget
  
  ## PHP AMQP
  RUN apt-get install -y librabbitmq-dev libssl-dev
  RUN pecl install amqp
  RUN docker-php-ext-enable amqp
  </code></pre>
  
  <p>And when i get to the point of pecl install amqp...</p>
  
  <pre><code>.......
  /tmp/pear/temp/amqp/amqp.c: In function 'zm_startup_amqp':
  /tmp/pear/temp/amqp/amqp.c:177:55: error: 'AMQP_SASL_METHOD_EXTERNAL' undeclared (first use in this function)
    REGISTER_LONG_CONSTANT("AMQP_SASL_METHOD_EXTERNAL",  AMQP_SASL_METHOD_EXTERNAL, CONST_CS | CONST_PERSISTENT);
                                                         ^
  /usr/local/include/php/Zend/zend_constants.h:42:105: note: in definition of macro 'REGISTER_LONG_CONSTANT'
   #define REGISTER_LONG_CONSTANT(name, lval, flags)  zend_register_long_constant((name), sizeof(name)-1, (lval), (flags), module_number)
                                                                                                           ^
  /tmp/pear/temp/amqp/amqp.c:177:55: note: each undeclared identifier is reported only once for each function it appears in
    REGISTER_LONG_CONSTANT("AMQP_SASL_METHOD_EXTERNAL",  AMQP_SASL_METHOD_EXTERNAL, CONST_CS | CONST_PERSISTENT);
                                                         ^
  /usr/local/include/php/Zend/zend_constants.h:42:105: note: in definition of macro 'REGISTER_LONG_CONSTANT'
   #define REGISTER_LONG_CONSTANT(name, lval, flags)  zend_register_long_constant((name), sizeof(name)-1, (lval), (flags), module_number)
                                                                                                           ^
  Makefile:194: recipe for target 'amqp.lo' failed
  make: *** [amqp.lo] Error 1
  ERROR: `make' failed
  The command '/bin/sh -c pecl install amqp' returned a non-zero code: 1
  </code></pre>
  
  <p>And here is the error I got, I don't really understand why it failed, because since now it worked fine... Anyone got any idea. Or a solution on how to install amqp without using pecl maybe ?</p>