Compile the ImageMagic library into some necessary configuration of the nginx server

1. Start by adding the appropriate header file of the ImageMagick library to the environment variable

export C_INCLUDE_PATH=$C_INCLUDE_PATH:/usr/local/ImageMagick/include/ImageMagick/

The following path will vary from person to person

Otherwise the following error will occur

wand/MagickWand.h: No such file or directory

2. Add the corresponding library when linking

In the obj/Makefile file, find the following line,

objs/nginx:     objs/src/core/nginx.o \

And at the bottom of this we add:

`pkg-config --cflags --libs MagickWand`

Output corresponding variables

export PKG_CONFIG_PATH=/usr/local/ImageMagick/lib/pkgconfig/

Otherwise, make will still make the following mistakes:

undefined reference to `MagickWandGenesis'

make

make install will do